I have your same problem. My two 256-Cruzers work fine on my Windows Millenium and Windows 98 (using SanDisk's downloadable driver) systems, but not on my new Windows XP Home system. I'm fairly computer literate --- and I've tried about everything. I've considered loading the Windows XP system disk and launching a search of that disk for the driver, but fear that a major catastrophy might ensue. I did force XP to search for a "driver" in "WINDOWS\system32\drivers," where the driver for my other flash drive (that works on XP) is known to be filed, to no avail. I know the USB plugs are good because another 256-CompUSA generic flash drive works fine on the XP system. I've talked by phone to SanDisk Support, but nothing was suggested that works; they emphatically say that no such thing as a "driver file or disk" exists for XP. If you find a solution, please post it.