Also, how do I check if my computer can handle 64-bit Windows Vista Home Premium? Thanks!

I am running windows vista on my pc but recently windows will not load or it displays ‘please insert CD’. This has never happened before. Any ideas?

will the vista be compatible with windows xp home edition? my pc is a fujitsu siemens and over 3 years old.
my current pc has 160gb memory and was top of the range when bought.

I bought a new computer that has vista home premium but some of my software from before is incompatible. Would it be ok to partition the hard drive and install xp on a seperate drive from vista. Would the computer give me the option which operating system to start when i switch it on.