I'm posting this for informational purposes, so other confused people can find all the info in one place. Hopefully there's enough keywords that they'll find it in a search. If you're using an app like Solidworks in v2.5 that requires a HASP USB key (dongle), and it has suddenly stopped working (giving an "another app is using the device" popup), then the problem is that you upgraded to OS 10.4.10. Parallels has a new build of 2.5 that fixes the problem. See: http://forum.parallels.com/showthread.php?t=13580&highlight=usb Download and install this new version. 3.0 apparently works fine, but I haven't coughed up the $50 yet... To get the HASP key to work, just boot into Windows, insert the key, and it should be recognized. If it is not, you may have to use the Devices menu in Parallels to assign it to the VM. If for some reason Solidworks still complains, use the XP Computer Management app, click on System Tools : Device Manager, then the [+] to the left of Universal Serial Bus Controllers. You will probably see a single item that says "Aladdin USB Key" or "Aladdin HASP Key". Right click it and select disable. Then right click again and enable it again. IIRC from when I was having problems last year, the issue was that while there are two devices inside the key (the USB and HASP parts), XP was only seeing the first one. But when you disabled and re-enabled it, it would then see both of them. Once you have both of the devices showing up under Universal Serial Bus Controllers, Solidworks (or whatever you're using that uses one of these silly things) will work fine.