many problems

Ok lately I have been having many problems. I have ran malware anti bytes I have ESET NOD3 running all the time on my computer. I cleaned everything malware found .. still nothing is improving.

Here is the list of problems i am having..

Internet explorer is just running majorly crappy.. freezes constantly, runs slow, adobe plug in errors
Mozilla Fire Fox keeps having Adobe plug in errors. runs slow and freezes..
I have to use Google Chrome just to navigate around the internet or go on facebook.
My incredimail wont start up if I have been on the computer for more than 15 mins. I will load if I open it as soon as I log on .. if not it just hangs there.
Games I have downloaded are starting to do the same.. if I dont play them before I am on the computer for too long they freeze while loading.

Any help would be appreciated.

Thank you in advance.