pc slowing down

in processes on the task manager i got loads of items running and i dont know what half of them are for infact its at the stage where my pc slows down when im gaming and games keep closing down to the task bar and applications like email take longer to open then normal how can i find out what should be running and what should'nt.

i need help big time pc is being strangled by it all running. plus i have my firewall/anti virus/pest patrol running at all times even if im just online gaming .i never use to have this porblerm with same amount of ram

Run hijackthis and post a log in the hijackthis forum

where do i get that from

HIjak This:

please follow owen's Instructions and then post your log in the Spyware, Adware, Viruses and HijackThis Logs section.

Also you might want to look over this list of Services:

Black Viper