I have a 320GB Apacer AC202 external SATA HDD, purchased in 2010. The device works flawlessly on my ancient laptop running Windows XP. I just got a new laptop, a Dell Latitude E6420 running Windows 7 professional (64bit). The HDD is recognized correctly once plugged in, and it is immediately listed as one of the disk drives in the device manager. However, it takes several minutes (between 5 and 10) before becoming visible in Windows Explorer. When it finally does, it is listed as drive E:\, but once I try to open it I get the error message "the semaphore timeout period has expired".

If anybody could help me fix this problem I would really appreciate it. Thanks.

Based on your description, especially that delay before the drive letter appears in Explorer, this is a filesystem problem and not a disk problem. If you Google/Bing for that error message, you'll see lots of people having that message mostly on Vista and Win7 systems. In some cases, filesystem corruption was found during later troubleshooting.

Before doing anything else [and assuming you accept that any DIY actions have risks e.g. due to human error, hardware failure or many other possible causes], I suggest you make a raw (sector-by-sector) clone of that drive, onto another one.

Depending on what level of suggestions you want, IMHO there are several possible troubleshooting approaches.

Thank you for the response. I just tried the hard drive on my wife's Lenovo X201, also running Windows 7 professional (64bit), and it worked perfectly. So it's somehow my brand new computer ...

Personally I suspect there's more to it than just that - for example, I expect that an external drive which has been freshly formatted, would behave correctly on that new computer. Anyway, I'll leave you to troubleshoot it from here, now that you have "good" & "failing" scenarios to work with. Good luck!

Drive freshly formatted, same identical behaviour. No idea what to do ...

I'm surprised, but filesystem problems were often reported to cause that error message for other people. However, other issues (e.g. LAN problems when copying files between PCs) also caused the same error message - which isn't surprising as a semaphore timeout is a part of the Windows API, and is used for timing many different operations.

Personally I would be checking the Windows event logs on the "problem" computer, to see if they suggest at a relevant area for you to investigate further. I would also check to see if the behaviour changes depending on the filesystem type (NTFS vs FAT32) on that freshly formatted drive, when it's connected to your "problem" computer, as well as seeing if USB memory sticks work OK. The idea being to narrow down (if possible) what needs to be different to provoke the problem, or not, on the "problem" PC. That will help to give you better search terms to use on Windows support forums, if the results suggest a Windows (rather than a hardware) problem.

Based on the result with your wife's computer, I don't see evidence of a disk-related issue. Of course providing that you have backups (in case of any unforeseen issues), if you wanted then you could run a read scan (e.g. using HDDScan) of the whole drive when it is attached to her PC, to confirm that there are no detectable read problems.

Other readers may have further suggestions, but based on the info given so far, I don't see evidence of a disk issue, and hence nothing that's likely to be on-topic for this forum. Unless you see something that points towards the disk as the cause of your problem?

you may:

1- try to change the cable and see
2- try to use other USB port and test

i only think about the cable

good luck

_________________
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I have seen these symptoms on external drives which can be caused by power problems. The fact you have found the drive to work flawlessly on other systems shows your new Dell may have a problem usb port.
Have you tried using one of those cables with dual usb connectors which allows for power to be drawn from 2 usb ports at the same time?

The drive comes with a Y cable. I have tried plugging both ends at the same time, but it didn't seem to make any difference. I have tried different USB ports in the machine as well.

Btw, another thing: I left the drive plugged in for a very long time (1+ hours) and at some point I was prompted to format it before use (even though it has just been formatted on a different computer). I tried, but when reached 100% an error message appeared saying that the action could not be completed.

As you have said the drive works ok on another pc.
You could try booting to an ubuntu boot cd on your pc. Then plug in your drive.
If it works ok then its your os is the issue if not then you know its your pc hardware.

Loki

I tried a different cable, didn't help. I borrowed another external hard drive, worked perfectly on my computer, as does my USB memory stick.

Looking at the Windows event log, an error messaged is logged when I connect the problematic drive. The source is "BitLocker-Driver", and the message is "Encrypted volume check: Volume information on E: cannot be read".

Why are encrypted partition?
In my opinion, you just need to re-create the partition and file system on disk. Do not forget to first save your files somewhere.
After this partition must have a code 07 (NTFS).
P.S. Or read this: http://technet.microsoft.com/en-us/library/cc734057(v=ws.10).aspx

@olkon


IMHO that's the wrong question. This Windows error message can be seen even there are no encrypted partitions!

@superpippo,

Thanks for checking for Windows events, as I suggested. If you Google about that "Encrypted volume check" event, you'll find other people reporting that error (without BitLocker enabled) on some disks, but not others. My brief research (you will need to do more) suggests that incorrect registry information related to BitLocker causes the behaviour you see, including delayed recognition of the affected disk (which also delays Windows starting, if it happens on an internal disk), but the same disk works fine on other systems, because on those unaffected systems, the registry is OK.

Since Windows "tracks" disks via the disk signature, which is not changed when a disk is reformatted, then this may explain why reformatting the "problem" disk did not fix the behaviour. It may also explain why other disks (& USB memory) work fine on the "problem" PC, since those other disks have different disk signature values.

I don't have the time to care about Windows problems, but if I was in your situation, I would do further research on that specific event, as I started to do - various suggestions are mentioned on other websites (including, but not only, the BitLocker Repair Tool linked by olkon).

I can think of a quick "hack" (only as a test, as it wouldn't solve any underlying registry issue), which would be to temporarily change the disk signature on that "problem" disk and see if it "fixes" the issue when that disk is attached to your "problem" PC, but I don't have time to write a full step-by-step list of instructions.

I hope those comments help, but as I said, you'll need to do the research. You'll see in your search resuts that you're not alone with that problem.

Yet I believe that the error associated with this partition, not the disc. Therefore, wrote that the need to repartition the drive and then create a file system (this is not the same thing, just to format the existing partition).
Unfortunately, I can not reproduce at this problem, to verify a guess, but topicstarter may well try it.

Partitions are tracked by Windows (via registry keys) too - but Windows support is off-topic for this forum, so unless there is evidence of this being a disk problem, I think there will be better places for the OP to get the help that he needs.

I agree with that.