Dell Inspiron 600m (Pentium 1.6 Ghz, 512 MB RAM, 60GB Hard Disk (50% free), Windows XP)
Once I start using internet (dial up), CPU usage reaches 100%. According to Windows task manager, primary users of memory and cpu are opera.exe (firefox and IE as well if I use them), Mcshield.exe, explorer.exe and svchost.exe. I tried changing priority of Mcshield.exe from high to normal but the system didn't allow me. I am not running any windows media player, messenger or p2p exchange software etc.- just simple browsing. Even if I kill opera.exe and stop using internet, CPU usage remains 100%.
I have scanned using McAfee anti-virus. I have already disabled automatic windows updates. Ran a dell tune up program to clean up; tried to defragment disk but the system's analysis was that it wasn't required.
I don't know if it's relevant but my laptop gets quite hot though there hasn't been any warning/automatic shutdown.
Can anyone suggest a solution ? Thanks in advance.