Which is the best suitable operating system for my pc

[Usman Alvi]

specifications
Pentium 4,
3.20 Ghz,
2 Gb RAM,
400 Gb Hard drive

What is the best operating system for my pc.. no linux or ubuntu, i've used it and did not like it.. an os easy to use and works well with old pc.

 

[Phillip Corcoran]

If it's a factory-built PC what make & model is it?
Need to know to that in order to check what Windows versions are supported (ie drivers).

Drivers aside, with only 2GB RAM I wouldn't want to use anything later than Windows XP without increasing the RAM to 4GB, or at least 3GB if you don't mind it being a bit slow.