enakoala:
The primary reason why that computer is running like a turtle is because it has only 256 MB of RAM. You need to add at least another 256 MB - and preferably more if the motherboard supports it.
Adding
Windows Live One Care and
PC Tools Spyware Doctor is bogging it down even more. Uninstall and get rid of both of them. Download and install
Malwarebytes Anti-Malware and
SUPERAntiSpyware in their place. They're more user-friendly and have much smaller system requirements.
Do you know how to post a HijackThis log of that computer?
--------------------------------------------------------------