Download and run AVG or Avast to check for viruses. Either is good

Also get Malwarebytes' Anti-Malware for check for other nasties.

Spybot search and destroy is another good choice.

All these are free, just make sure to download them from their offical sites.

BTW - leave them on the machine and run them at least once a month, because email is one of the most common ways for a machine to catch a cold.

Pinky - you left the lens cap of your mind on again.