Hey Hey,

I've got the Visual Studio 2005 Express Editions running under Vista without a problem... If it's working one one of your Vista systems (laptop) and not on the other (desktop) I'd say it's a conflict of some sort... Can you think of anything you've added to the desktop that's not on the laptop (Specific SDKs or anything)

As for your install error... the net is full of suggested fixes:

Remove the VS folder in %program files% (it isn't fully cleaned up by the uninstall)
Remove the Office Tools for VS application
Ensure that you are using proper (original) media.. If not.. copy the contents of the disks/dvd to a single folder on your harddrive... certain "compilation" DVDs have been known to not work... as have "personal backups"
Install "Windows Installer 3.1"