Upgrade to Vista?

Can I uninstall Windows XP and install Vista on the same machine?

Would my PC restart with no OS on it before I install Vista probably by cd-rom

If you buy an upgrade version of Vista it will overwrite XP.

If you want a full retail version you would format the partition/drive during install removing XP or you could load Vista as a second OS (dual boot) along with XP.

A computer needs some operating system to go beyond the BIOS.

Ive never really understood dual booting. When do you get to choose which OS you use?

Usually right after the BIOS POST before Windows loads.

If the Boot.INI recognizes 2 (or more) Operating Systems it should prompt for which to load.

There are also third party boot managers if windows doesn't "get it".

I'd be going for Vista retail version primarily for improved performance and graphics for gaming
So how do I partition my hard drive to keep OS apart. When Vista is installed can I then remove XP from the hard drive.

If you do not want XP then let Vista overwrite it i.e. format the hard drive.

In the early stages of installing Vista you will be asked where to install it. You should see a list of all your partitions (if you have more than one).

If the hard drive or partition has a previous installation of XP you want to remove, choose to delete the partition by pressing "D". You will then be prompted to create a new partition in the empty space. This will remove all data from the deleted space.

Then install Vista here. Verify that it is designated C:.