disk error - 108 occurred while reading or writing to a scratch disk.

I have a pentium 4 laptop whith windows xp installed and i have 20g of free space on disk and 512 of Ram, and while using photoshop cs2 it keeps giving me this error "disk error - 108 ocurred while reading or writing to a scratch disk. sorry, but this error is unrecoverable." It's impossible to do anything because everytime i get that message i have to close the program and reopen it and do everything again.can someone help me to correct that problem?

Most likely you've got a problem with the disk, cables, controller or formatting.

Some older viruses were also known to cause disk errors like that.