WinXp Problem

Recently i noticed when i Open Yahoo messenger and click on Email, Firefox stops working and internet in firefox doesn't work everything else works ET, Music stream etc, when i close firefox it won't open again, when i shut down PC it takes over 1 minute to shut down instead of 5 seconds, has anyone had this problem before?

Programs used to scan:

Combofix
Spybot search and Destroy
malwarebytes
iobit malware fighter
eset online scanner