What is the best tool for checking my PC?

i have a windows XP serv pk 2 notebook and i want something free that can do at least 2 of the fallowing

check for spyware, malware, viruses and errors

speed up preformance let me chooses my start-up programs and free up space

diagnose problems

easy to use

please no trial software!

What is the best tool for checking my PC?pop up blocker

avg free edition is good for everyday, and "ad-aware" is what i use for checking things you mentioned.

i suggest looking through what "download.com" has to offer.

What is the best tool for checking my PC?systemworks

AVG works pretty good and is free. Go to www.download.com and do a search for AVG. Hope that helps!