Here are some free suggestions to protect yourself from Virus, Trojans and Email Hacks in this order.
1) Download and Install Spybot Search and Destroy. This will scan and eliminate spyware, adware, key loggers, browser hijackers and trojans.
http://www.safer-networking.org/en/mirrors/index.html
2) Download and install Microsoft Security Essentials or AVG Anti-Virus Free 2012 (The free edition only. The Internet Security Edition is not needed)
http://windows.microsoft.com/en-US/windows/products/security-essentials/download
or
http://free.avg.com/us-en/homepage
3) Change your email password to a strong password using numbers, mixed case or special characters once your computer is clean. (This will make it harder for brute force password guessing programs to guess your password)
Randpass.com can help you with choosing a stronger password.
http://www.randpass.com/
Optional
1) Switch to Gmail and use Google Authenticator that requires your email password and an additional password sent to your mobile phone or designated voice telephone to access your email.
http://support.google.com/accounts/bin/answer.py?hl=en&answer=1066447
2) Use LastPass to help keep track of all your web passwords and generate secure password
https://lastpass.com
