Install Vista as dual boot with only the upgrade disk

I brought the vista upgrade disk which will upgrade my windows xp. However I want to keep this copy of xp and dual bot vista from another hardrive .

IS this possible?

 

if its just an upgrade then you need the previous os to install it, just make a partition, install xp, then vista upgrade.

 

Sounds reasonable but will i have to activate windows xp

 

not to my knowladge

 

OK thanks alot. Another question though.

Is there any way to install vista with less than 512mb ram? because i only have 256mb. Could there be an application or something that makes it think it has 512mb ram when it doesn't

 

srry but that impossible. Even if something like that existed the os wouldn't install because it know the ram when its installing, you need 512 to be able to run the new programs and stuff the os uses

 

Sounds reasonable. Thanks

 

np make sure you buy compatible ram for your motherboard