Can one Antivirus remove all the virus one pc have?
Depends on the Anti-virus and the version you have but I always run a Malware scanner as well. Note that you should not run 2 scans in the same time, sometimes they interfere with each-other.
Several independent labs publish test results showing how well various anti-virus remove viruses. AV-comparitives is one of the most comprehensive:
For more general results, look here: