Installing applications on XP Pro

I am in the process of planning my move to XP Pro. I have bought the software but will not install it until I understand the issues. I am currently running Win98SE.

I have learned from bitter experience that it is best to shut down applications (particularly my antivirus software (Norton Systemworks 2003). I normally use Enditall2 to do this – although this also disables the very useful Systemworks facility allowing a return to an earlier configuration.

So my question is: Do I have to uninstall running applications in XP Pro before starting to install new software applications? It’s a pretty time consuming process so if there is a way round it I would love to know it. Thanks in advance.
John