Helping people with computers... one answer at a time.
I/O device errors indicate a problem with storage media you're attempting to read from or write to. I/O device errors should not be ignored.
I tried to copy a file to my flash memory, while I was copying this error message appeared "Cannot copy (file name): the request could not be performed because of an I/O device error" and I don't know why?
Well, it's hard to say exactly why it happened, though of course I have theories.
The real question is what to do next. In the case of a flash drive, the answer's fairly clear. In the case of other types of media, there additional options.
"I/O" stands for Input/Output, so an "I/O Device" is the Input/Output device you happen to be using at the time. An "I/O Device error" means that some kind of unrecoverable error happened on that device.
The device, of course, could be either the device that contains the file you're copying - in other words an error reading the file - or the device you're copying the file to - in other words an error writing the file.
If you can copy the file anywhere else - like perhaps a different hard disk - then the problem is likely to be writing to the destination, which in your case is the flash drive.
As I've written about before, flash drives wear out, and cheap ones wear out most quickly. When they begin to fail they start showing errors exactly like what you're seeing.
When this happens you really have only one option: copy off all the data you might want to preserve from that flash drive, and replace it with a new one. Simple, and hopefully effective if you do it as soon as the flash drive starts showing problems.
If the problem happens with a traditional hard drive, regardless of whether you're reading or writing the drive, it's typically due to a bad sector on the hard drive, and you have a couple of options:
CHKDSK /R, or Check Disk, is a drive maintenance utility that comes with Windows. The /R option locates bad sectors and attempts to recover readable information. (If this is your system drive, CHKDSK may require that you schedule the operation for the next reboot of your computer.)
SpinRite is a commercial product drive maintenance utility that, for lack of a better description, does a kind of low-level format of your hard drive without losing your data. In fact, SpinRite can often recover the contents of bad sectors that other utilities, including Chkdsk, cannot. The result is that a drive can often be recovered, repaired and then safely used again.
Of course if the data cannot be recovered, and the drive cannot be repaired, then you'll need to replace it and restore from your backups.
The bottom line, though, is that an error like this should not be ignored. Depending on what device is actually exhibiting the error, you may have an immediate problem, or you may have a warning sign of a disaster yet to come.