Data Recovery Case File · Desktop Externals & Aging Drives · One Device, Whole System
The Drive That Slows the Whole Computer
His enquiry described a symptom people rarely connect to a single device, and asked for exactly the right thing. An external drive that "is recognised by Windows, but it takes forever to open anything in Explorer. Additionally, my PC runs slower when the drive is connected. How much would it cost to make a copy of the drive please?" Two points. The whole computer slowing down is not a coincidence or a separate problem — it is the clearest possible sign that the drive is failing reads, and it explains itself once you know how a computer waits. And his request — a copy, made now, rather than a repair — is the right instinct, and it is what a bench does.
| Media | External hard drive recognised by the host — severe delays opening contents; host system performance degraded whenever the drive is connected |
| Reported situation | Drive enumerating and mounting normally · file listing and access extremely slow · overall system performance affected by the drive's presence · owner requesting a copy rather than a repair |
| Fault class | Read failures with escalating retries — drive stalling the host storage subsystem; window open but closing with use |
| Equipment used | Atola Insight Forensic surface and error-rate assessment · PC-3000 Express with Data Extractor imaging under per-sector timeouts · healthy regions banked first, weak neighbourhoods deferred · image verified and written to new media |
The decode: why one drive slows everything, and why a copy is right
How a computer waits: when anything asks for data, the request goes to a storage driver which asks the device and then blocks until an answer arrives. On a healthy drive that is milliseconds. On a failing one the drive retries internally, and the answer can take seconds — or never come. The driver waits, and because storage handling is shared machinery deep in the operating system, other things queue behind it. That is why a single failing external drive can make an entire computer feel unwell: the machine is not slow, it is waiting, and it is waiting on the one device that will not answer.
Why that is a useful diagnostic: it distinguishes a failing drive from a merely slow one. A drive that is old, fragmented or connected over a poor interface is slow to transfer and does not affect anything else. A drive that drags the whole system down is producing timeouts, and timeouts mean reads that are not completing. That is a hardware-level symptom rather than a filesystem one, and it means the clock is running.
Why his instinct is correct: he has asked for a copy rather than a repair, which is precisely the right sequence. A drive in this state should not be trusted afterwards regardless of what could be done to it, and the goal is to get the contents onto something reliable while the drive still answers at all. Waiting for a convenient moment is how these windows close.
Why ordinary copying will not do it: the refinement that matters. Consumer copying and cloning tools have no way to give up on a sector and return to it later — they wait, retry, and either stall indefinitely or abort with a partial result and no record of what was missed. On a drive already taking seconds per read, that means days of hammering the weakest regions while copying very little. Imaging under per-sector timeouts is the same intention done properly: each failing sector gets a strict budget and is deferred, the healthy expanse is captured first at full speed while the drive is at its strongest, and the difficult ground is revisited afterwards on its own terms.
What to do immediately: disconnect it. Every minute it is attached, the machine is issuing requests and the drive is retrying — and browsing it to see what is still there is the most expensive way to spend the margin he has left.
On the bench
The Atola Insight Forensic assessed surface condition and error rates directly, establishing whether the degradation was localised or general — the difference between a bounded problem and a drive in decline, and the measure of how much margin remained. Imaging then ran on the PC-3000 Express under Data Extractor with per-sector timeouts enforced: the healthy expanse captured first at full speed, weak neighbourhoods deferred to later patient passes, and the sweep sequenced by priority rather than disk order. The completed image was verified and written to new media, with any unreadable regions resolved to the files they affected.
The outcome
The drive imaged under timeout control, the contents verified and written to new media, and the failing drive retired. Free assessment, one fixed written figure including VAT; where a drive has to be opened, 50% of parts and labour is payable upfront with the balance only on success — otherwise no recovery, no fee. The decode, for anyone whose computer slows when a drive is attached: that is not two problems but one — your machine is waiting on a device that will not answer, and because storage handling is shared, everything queues behind it; a drive that is merely old or fragmented is slow to transfer without affecting anything else, so a system-wide slowdown means reads are timing out, which is hardware-level and time-critical; asking for a copy rather than a repair is exactly right; and disconnect it rather than browsing to see what survives.
One drive making the whole machine slow
Unplug it, and take the symptom seriously. A computer that drags whenever a particular drive is connected isn't suffering from two problems — it's waiting. Every request for data blocks until the device answers, and because storage handling is shared machinery inside the operating system, everything else queues behind the one device that won't respond. That's a meaningful distinction: a drive that's merely old or fragmented copies slowly without affecting anything else, whereas one that slows your whole system is producing read timeouts, which means the clock is running. Don't browse it to see what's still there — that's the most expensive way to spend what's left. If you're copying yourself, work in strict priority order and accept you may not get everything. And be wary of consumer cloning tools, which stall for hours on the first bad region and often abort with no list of what they missed.
Unplug it and copy properly — call Glasgow Data Recovery on 0141 404 0294; surface measured, imaged healthy-regions-first under per-sector timeouts, verified onto new media.
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Our case files are drawn from genuine enquiries received by our laboratory over the past ten years, anonymised to protect client confidentiality. Each one describes the diagnostic and recovery procedure our engineers apply to that fault, using the equipment listed.