The cameras did their part. Then the recorder failed, or the loop came round and recorded over the week that mattered, or somebody hit reset while tidying up the office. Footage gets carved back off DVR and NVR drives here for households, shops, pubs and clubs, insurers and solicitors right across Bracknell and Berkshire, including the yards, depots and trading estates along the A329M and out towards Slough, where a camera on a pole is often the only witness anybody has.
Anything sent in for CCTV or DVR recovery is diagnosed free. The written figure that follows is settled before a screwdriver leaves the drawer: £400 + VAT for a CCTV or DVR recorder drive.
No fix, no fee covers logical recoveries. Outside it sit electronic and mechanical failures, chip-level work, DVR jobs and forensic jobs, and physical work is 50% up front. Every band is published on the data recovery cost page.
Reading a symptom back to the failure underneath it is where the work genuinely starts, and this set of thirty accounts for all but a handful of the parcels that reach the Guildford bench. If yours is not on the list, it will still be recognised — describe it on the phone and you will get a straight answer about the odds before you post anything.
The hardest sentence on this page, so it comes first. A recorder writes continuously and then starts again at the beginning, so footage has a shelf life measured in days rather than years. Eight cameras onto a 2TB disk at a normal bitrate is roughly a fortnight before the oldest recording is overwritten. Overwriting is untidy rather than systematic and fragments of older material often survive in regions the loop has not reached yet, but every further day of recording reduces that. Take the recorder off the wall today rather than at the weekend.
A surveillance drive never idles. It writes constantly for years, which is a duty cycle nothing on a desktop approaches, and it wears out accordingly. Purples and SkyHawks are built for it and still reach the end of their lives on this bench regularly. A disk that has begun to stumble is imaged under retry control rather than left running in a box that will keep writing to it.
Fitting an ordinary desktop disk into a recorder to save thirty pounds is common and it does not end well. Those drives are specified for a fraction of the workload, and they fail earlier and more abruptly than the surveillance models. Recovery is the same process either way, so the saving simply buys an earlier appointment with us.
Hikvision, Dahua, Swann, HiLook, Annke, Uniview and the long queue of rebadged units built on the same boards generally write raw video straight onto the platter without anything Windows would identify as a file system. That is why a recorder disk connected to a PC appears blank. The structures are proprietary and they are parsed directly here, from a sector-by-sector copy rather than from the disk itself.
A deletion made through the recorder removes the index entry and leaves the video where it was until new recording claims that space. This is one of the more recoverable situations on the page, provided the unit stops recording immediately. Switch it off, take the disk out, and get it into the post.
Power supplies and boards fail constantly in these units, which spend their lives in cupboards and roof spaces. The disk inside is usually untouched. Send the drive on its own: no equipment is dismantled at this end, and there is nothing to be gained from posting the whole box.
An engineer resets the unit to clear a fault, or a new installer starts from scratch, and the archive goes with the configuration. The reset writes very little to the disk itself, so the recordings are generally still there underneath. What ruins it is the unit being left running afterwards.
The point of stealing the box is the footage inside it. Where the disk survives in a damaged chassis it is usually readable, and where the platters have been physically struck the work becomes mechanical, in filtered air with matched donors. Bring what is left, however unpromising it looks.
Water and heat damage the electronics long before they reach the platters. A drive out of a flooded unit is cleaned, dried and given a donor board where needed. Do not attempt to power it up to see whether it still works, because that single action turns a recoverable disk into a destroyed one more often than any other.
Material that has to hold up as evidence must be shown to be unaltered rather than merely watchable, and those are different standards. Work is carried out against hash-verified copies, and a written account of the handling runs from the moment the packaging is opened to the moment it goes back. Exports carry their own integrity hashes where the recipient wants them.
Most recorders keep a small database describing what was recorded and when, sitting apart from the video data itself. Damage that and the unit reports an empty archive while hundreds of hours remain on the disk. Carving works from the stream structures directly and ignores the index entirely.
Channels drift apart when a recorder loses its network time source, so exported clips carry timestamps that contradict each other. Streams are tied back to the channel that produced them and to the clock the recorder was actually keeping, and any offset is documented rather than silently corrected.
A recorder that loses its clock battery restarts in 2010 or 1970 and writes new footage with those dates attached. The playback calendar then makes no sense and the search finds nothing. The recordings are still there in write order, and the timeline is reconstructed from that order rather than from the labels.
These write to a memory card and loop it to exhaustion in exactly the way a recorder loops a disk. A card worn out by that duty cycle is read at chip level on the flash bench, and memory cards and pen drives are £250 + VAT. The warning about time applies just as strongly here, since the loop carries on regardless of whether anybody has decided what to do about it.
Recorders end up in meter cupboards, stock rooms and lofts with no ventilation at all. A drive running at fifty degrees for three summers ages several times faster than the specification allows, and it usually fails in August. Heat is the most predictable cause of failure on this page and the easiest to design out.
Some units write their own signature onto the disk and refuse to read a drive that came out of a different box, which is why swapping a disk between two identical recorders does not work. It makes no difference here, because the disk is read directly rather than through a recorder that has opinions about where it came from.
The screen showed live pictures the whole time, so nobody noticed the archive had stopped growing. Then something happens and there is nothing to look at. Where a disk failed silently, what was recorded before it stopped is often still recoverable, so it is worth asking rather than assuming.
Recorder export functions are frequently the least reliable software in the building, and a failed export can leave the database inconsistent. Nothing here uses the unit menus or its export function at any point, which is fortunate, since that is often how the footage went missing to begin with.
H.265 and the various smart encodings save space by writing full frames rarely and describing changes in between. That is efficient and it makes carving harder, because a fragment without its keyframe has nothing to reconstruct from. It is worked around by locating keyframes first and rebuilding the sequences that hang off them.
Four-bay recorders sold with one disk fitted are everywhere, and the empty bays are why an archive lasts three weeks instead of three months. Nothing to recover from an empty bay, but it explains why the date you need has gone, and it is worth fixing before the next incident.
Motion-triggered recording only writes when the sensor fires, so a person walking in from an angle the sensor never covered leaves no footage at all. That is a gap in the recording rather than a fault in the disk, and no amount of laboratory work creates video that was never written.
Locked out of the menus is not the same as locked out of the footage. The disk is read directly here, and the recorder password has no bearing on that at all. Send the drive and a note of the make and model of the unit it came from.
Larger NVRs stripe video across several disks, which makes them an array rather than a recorder with a big drive. All members must travel together, they are imaged individually, and the set is reconstructed from the copies. Those jobs are priced as arrays, from £500 + VAT.
Proprietary export formats and player executables that no longer run on a current version of Windows are a recurring problem, particularly where footage was exported years ago and archived. Streams are converted here into ordinary video files that open on any computer, with the original timing kept intact.
Fitting an 8TB drive to a recorder that was designed around 4TB produces strange results: recording that wraps early, a calendar full of gaps, or a unit that reports the disk as full when it is not. The data written before the confusion is usually intact and is read from the copy without reference to what the firmware believed.
A long external run acts as an aerial in a storm, and the surge arrives at the recorder through the camera inputs rather than the mains. That kills the board and sometimes the drive electronics with it. Board work takes 50% of the quote upfront, and DVR jobs sit outside no fix, no fee in any case.
Windows sees no file system it recognises and offers to initialise the drive. Accepting that writes a new partition table over the top of the recorder structures, which is recoverable but entirely avoidable. If you are asked whether to format or initialise anything, the answer is always no.
Divide the disk capacity by the daily write rate and you have the length of your archive. Sixteen cameras at high bitrate onto a 4TB disk can be under ten days. Owners routinely believe they have months. Working that figure out for your own system takes five minutes and is the single most useful thing an installer never told you.
People discover something happened three weeks ago and go looking for it while the cameras carry on recording. Each day the loop runs, more of that period disappears. If an incident matters, take the disk out of service immediately, even if you have not decided what to do about it yet.
The free diagnostic examines the disk, tells you honestly what is actually on it and what is genuinely retrievable, and closes 2 working days after the drive is booked in. The figure that follows is fixed in writing before any work begins. DVR and CCTV jobs sit outside the no fix, no fee guarantee, so that figure is agreed and settled before the work runs rather than afterwards.
No two manufacturers store video the same way. Hikvision, Dahua, Swann, HiLook and Annke, along with the long queue of rebadged units built on identical boards, generally write raw streams straight onto the platter without laying down anything a Windows machine would identify as a file system. The software used here parses those proprietary structures directly. The disk is copied sector by sector first, the streams are then lifted out of the copy, each is tied back to the channel that produced it and to the clock the recorder was keeping at the time, and what you receive is a set of normal video files that open on any computer with the original timing preserved. Nobody touches the unit's own menus or its built-in export function at any stage, which is fortunate, because one of those two is very often how the footage went missing to begin with.
Material destined for the police, an insurer or a courtroom has to be shown to be unaltered, not merely watchable, and those are different requirements. All work is therefore carried out against hash-verified copies, and a written account of how the drive was handled runs from the moment the packaging is opened to the moment it goes back in the post. Where the recipient wants them, exports are supplied with their own integrity hashes attached. Supply the date and an approximate window of hours and the carving is directed there ahead of anywhere else, which makes an enormous difference on a disk holding several months of continuous recording. The figure is set in advance and does not move: £400 + VAT for a standard recorder drive. CCTV sits inside the forensic category, which means the amount is paid before work starts rather than on the strength of what comes back.
Video recorders store data in ways nothing else does, so this bench carries tooling that no other page here needs:
Hikvision, Dahua and the rebadged boards built on them all write their own structures. Those are read directly from a copy of the disk rather than through the recorder, which has no part in the process at any stage.
Fragments are tied back to the camera that produced them and to the time the recorder was keeping when they were written, so what you receive is organised rather than a heap of clips in no order.
Surveillance disks arrive with heavy bad-sector loads because they have written continuously for years. They are captured under hardware retry control, weakest regions last, with nothing left running unattended.
Every copy is hash-verified and the handling is documented from the moment the parcel is opened. Where evidence is the purpose, that record matters as much as the footage does.
Recovered streams are converted into ordinary video files that open on any computer, with original timing preserved. No proprietary player and no ageing executable is needed to watch them.
Recorder disks are read-only in hardware from the moment they are connected. Nothing in this workflow can write to a drive that arrived with footage on it.
Most own-brand recorders have a Hikvision or Dahua board behind the badge on the front, which is helpful, because it means the same handful of formats covers the great majority of what arrives. The DS-7200 family alone accounts for a startling share of what is fitted across Bracknell town centre, the retail parks and the trading estates out towards Slough and Camberley. Inside them, turning without a pause for years at a time, sit the surveillance drives: WD Purples, Seagate SkyHawks, and whatever was cheapest on the day. Every job therefore opens with an inspection and a full image, and nothing is carved until that capture has finished. Send the drive on its own wherever possible, with a note of the recorder make and model and the dates and times that matter, because a stated window is directed at first and that makes an enormous difference on a disk holding months of continuous recording. Where the recorder itself has to come, telephone 0800 689 0668 before packing anything and we will settle what should be in the box.
Nearly every job here arrived as a parcel. Tracked, insured post is the calmest way to move a drive that is already struggling, and something handed over in Berkshire, Surrey or London is normally on the Guildford bench the next working day.
Is the storage still bolted into a machine — laptop, tower, iMac, MacBook, rack server, a DVR under the till? Free it first and send the bare unit. Stripping hardware is not something this lab does, though it is ten minutes' work for any repair shop on your high street. There is a single case with no way round it: memory chips soldered flat onto the mainboard, which is how Apple Silicon machines and certain ultrabooks are built. Where the storage cannot be unbolted, there is no parcel to make up.
↓ Print the shipping & booking-in form (PDF)
The name on the parcel wants to be Guildford Data Recovery. Driving it over from Bracknell is roughly forty minutes on the A322 then the A3; posting it costs you a stamp and a day. Either way, a message goes out to you as soon as it is logged onto the system, and two working days later the diagnostic is finished.
Unsure whether something should go in the box? Ring 0800 689 0668 while the lid is still open, or work through the free online diagnostic and let it tell you.
Nothing to pay for the diagnosis, one written figure before any work begins, and the band on this page is £400 + VAT for a CCTV or DVR recorder drive.