AMD Sempron 140

[gamor]

Hi everyone:
I'm from a small town in Argentina and have a problem with a processor.
I own a cybercafe and have an Asrock N68-VS3 UCC, 2 GB DDR3, NVIDIA GeForce 7025 integrated, with an AMD Sempron 140 2.7 Ghz. I need to have installed Counter Strike 1.6 and CS 1.5, and lots of other games as well, but this two are priority. The games run slowly with lag (all of them), but their are not played on Internet (we don't have enough connectivity for that, only LAN).
On another PC I have the same processor but a different MB and RAM (ASUS M2N-VM HDMI, 1 GB DDR2, NVIDIA GeForce 7050 integrated), the performance is almost identical (gets a little better with this last one).
The rest of the PCs are ASUS M2N-VM HDMI, 1 GB DDR2, NVIDIA GeForce 7050, AMD Athlon 64 X2 4200+, on this other machines I have absolutely no problem.
I think the processor is the culprit. I know there's a hidden core on AMD Sempron 140 to easely unhide with the Asrock N68-VS3 UCC, but don't want to do that, I MUST be able to play CS 1.5 and CS 1.6 with that configuration!
I thoutht Windows were the problem, but made a clean installation, update NVIDIA drivers, update to june 2010 Directx 9.0c, and the results: identicals.
My system: Windows XP Pro Colossus Edition (SP2 native, later I installed SP3), .NET version 4.
I bought the processors as PIB (Processor In a Box), they contained a mini CD, when I try to install it says that it's only for Windows 7.
Any clue about this one folks?

[Aloke]

Yes you were correct why don't you upgrade your processor as of now if you want to go ahead with the AMD processor then AMD Athlon II X2, AMD Phenom II X2 Black, AMD Phenom II X4 Black, AMD Athlon II X3 processors are some of the options that you should check out.

In Intel there are various processors such as Intel core i5, Intel core i7. So you can go with any of them.