My Vista Home Premium seems to be going well after 5 months of abuse.
Still boots up fast and doesn't crash at all.
I bought an Acer T180 5000 box with 2GB Ram from Comet.
It also goes a lot faster (I think) without the preloaded Acer crap - Norton Internet Protector, and a few bits and pieces serving no useful purpose were removed.
Installed AVG, use Windows Firewall, Webcam, 8 PC Games, webcam, Wireless dongle, various camera software, various music/MP3 software - the list goes on and it's still stable.
I use CC Cleaner weekly to remove internet crap and registry errors.
I also run a regular full system scan using AVG.
Defragged a few times . . . . and still stable !