Windows XP Pro/Windows Vista Home premium dual boot ftw?

[alvino]

Well Vista only needs 15GB because of temporary files during installation. When it's done installing, usually the size shrinks down to about 8GB. Program files also get installed in the same partition, so you may want to watch out for that.

 

[dude_se]

my vista partition was about 10gb and i still had about 1gb left over, even with some small files and programs like msn, limewire, etc. it just depends how big you need it (you can always store stuff on the xp partition). 10gb minimum id say. ive ran a dual boot on my laptop before. its quite cool switching between os's