Your computer keeps locking up for a few seconds, then carries on. Folders take forever to open, a file copy crawls to a stop, and some documents won’t open at all. It’s easy to blame an old PC, a virus or a bad update. But these are also classic signs of a hard drive with bad sectors, and if that’s the cause, the clock is running. A failing drive usually gets worse with use, so the choices you make in the next hour can decide how much data you get back.
Why a failing drive makes a computer freeze
A hard drive stores data in small units called sectors. When a sector starts to go bad, the drive doesn’t give up right away. It tries to read the same spot over and over, sometimes for several seconds. While that’s happening, whatever asked for the data has to wait, and that can include Windows or macOS itself. The whole computer seems to hang, then recovers when the drive finally returns the data or gives up.
A slow PC is usually slow all the time. A drive with bad sectors tends to feel normal, then stall when it reaches a damaged area. Those stalls are the clue.
Signs it’s the drive and not the software
- The system freezes for several seconds, and the mouse may still move while nothing responds.
- A file copy slows to almost nothing or stops at the same file each time.
- Windows shows errors like “The request could not be performed because of an I/O device error” or “Cyclic redundancy check” (CRC) when opening or copying files. On a Mac, you may see error code -36.
- Certain files or folders always cause a hang, and others open fine.
- The computer takes much longer to start than it used to, or sometimes doesn’t start at all.
- The drive light stays on solid during a freeze.
- You hear repeated soft clicks or ticking during a stall.
- Windows Event Viewer lists disk errors, such as “bad block” warnings.
Plenty of other things can cause slowdowns, including too little memory, malware and overheating. If you see several of the signs above together, though, treat the drive as failing until you’ve proved otherwise. SSDs can show similar stalls, but they fail in different ways. See our page on SSD data recovery if your computer has one.
What to do right now
- Stop non-essential activity. Close your programs. Pause cloud sync, antivirus scans, indexing and scheduled backups. Each of these reads or writes across the whole drive.
- Decide what matters most. Make a short list, such as business records, tax documents and family photos. If you could only rescue one folder, which would it be?
- Copy that first, in small batches. Plug in a healthy external drive and copy your most important files before anything else. Don’t drag your entire user folder across, since one bad file can hang the whole job.
- Skip anything that stalls. If a file hangs, cancel and move to the next one. Don’t keep retrying it. Repeated attempts wear on the weak area.
- Shut down if it gets worse. If freezes get longer, or you hear clicking, turn the computer off. A drive with a failing head can start damaging the disk surface, and at that point a professional recovery is the safest option.
Only do this if the drive is still fairly responsive. If the data is irreplaceable, the safer call is to power down now and have the drive imaged, rather than copying anything yourself.
What not to do
- Don’t run CHKDSK with repair options, or First Aid, over and over. A full surface scan puts hours of stress on a dying drive, and repair tools change the file system. That can hide or remove files that were still recoverable.
- Don’t run a “full scan” or surface test just to confirm the problem. Reading the SMART status is quick and safe, though a clean result doesn’t prove the drive is healthy. Long surface tests are hard on failing drives.
- Don’t defragment. It moves huge amounts of data around on weak media.
- Don’t reinstall Windows or macOS, or update your system, hoping to fix the freezes. An install writes to the drive, and major updates are heavy disk jobs.
- Don’t use a “bad sector repair” tool. Software can’t fix physical damage. At best, it marks the area to avoid. At worst, it overwrites sectors that might still have been readable.
- Don’t run a long recovery scan on the failing drive unless a pro has told you it can handle it.
Why cloning comes first in a recovery
The professional approach is built around one idea: read the failing drive as few times as possible. An engineer uses imaging equipment that can control exactly how a drive is read. It takes the easy areas first, skips past bad spots rather than getting stuck on them, and returns to the difficult sectors later with careful retries. The goal is a complete copy on a healthy drive, and all the file work then happens on that copy, not the original.
This is very different from what happens when Windows hits a bad sector, where it may keep trying the same spot until the drive gives up or the system crashes. That’s why a drive that seems hopeless on your desk can often be imaged far more completely on proper equipment, provided it hasn’t been run into the ground first. If the heads have failed, the drive may need physical repair before imaging can start. Our hard drive data recovery page has more detail, and how it works walks through each step.
Once your data is safe
Replace the drive. Bad sectors that have started to appear are rarely a one-time event, and a failing drive shouldn’t go back into service, even if it seems to recover after a restart. Your computer may be fine with a new drive or SSD, which is also a good time to set up an automatic backup to a separate location.
Computer freezing and you think it’s the drive?
Don’t wait for it to stop altogether. Shut it down and call Data Retrieval at (213) 986-4855. An engineer will evaluate the drive and give you a fixed quote, and recovery starts only when you approve it. We serve Los Angeles, the Inland Empire and Ventura County, and we accept mail-in drives from anywhere in the US.