I, like you, own a scanner but mine is the Epson Perfection 1670 which is constantly on. However, my scanner appears in XPs "Device Manager" under "Imaging Devices".
So my simple question is, does your scanner appear in your device manager, whether you can use the scanner or not?
PS. I have a screen print of how my "Device Manager" looks but could not attach it to this post.
If I don't use my winxp desktop for a while, it forgets the scanner driver. The scanner remains plugged in, the machine may be left on as print server for my home network. I use a Dell XPS 720 running win xp pro/media center 2005 with all updates. I can reinstall and all is fine for a while. Can anyone help? Scanner is HP scanjet 3970.