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.

BENQ instructions now gone

Does anyone still have copies of the BENQ instructions "How to install my P-model scanner in Windows XP" or anything roughly similar? Nothing like that seems to be available from BENQ any more.

So far, my efforts to install mirascan 3.42 on my XP system still produces a "scanner not found" message. If the instructions included anything other than the straightforward setup.exe method, I'm missing it.

I need for my Acer 620ST to keep working, because it scans transparencies as well as opaque matter, and that feature is hard to find.

Thanks to anybody who can help.

i'd put to use the fantastic resources of www.driverguide.com