Benchmarking software: Please recommend free version

[Hectic]

I've never tried benchmarking software, but need to check a pc ito performance to gauge if it is improving or not.
It is a Windows pc.

I would appreciate some software recommendations.

 

[GreyBush]

Futuremark, intel burn test, furmark, Heaven...

 

[The_Ogre]

Which components? For CPU/RAM I know SuperPi used to be quite popular.

I am however out of the overclocking arena for some years now

 

[Hectic]

Thx for the feedback.
No overclocking involved.
The pc is terribly slow, even after a clean install and want to try and see if there are improvements when I try something.

There was a Celeron 1.7 or 1.8 in and has been upgraded with an Intel cpu somewhere in the 3GHz region. PC is not here yet, so I'm not sure.
It is a G41 motherboard.
Performance were definitely sub par with the Celeron though. 2GB ram and 9400 PCiE
I did check hard drives and ram.
Moved from Win 7 to XP with same result.