For problems with the Acer 620P and probably other Acer scanners in operating systems beyond Win98 (definitely XP), do the following: First, BENQ now owns Acer scanners. Go to: http://www.benq.com/drivers/imaging_drivers.html for the new version of mirascan_v3424p.exe. (You can also find it at other download sites.) Then download and read the installation instructions from BENQ. You'll see a link to installation instructions. From there, click on "How to install my P-model scanner in Windows XP" Or go to: http://www.benq.com/ss_download/drivers/imaging/installation/mira3423_photoex_install.pdf These instructions are the key. After two days of struggle, the above method worked perfectly. The only trouble was I couldn't see the scanner in their last step (refresh step.) I had to restart, and then everything was fine. Good luck.