Aside from cleaning your computer, it needs protection. This must be done during the first installation of operating system, to ensure security at the very start. There are two great free antiviruses: AVG and Avira. I have tried them both and and they are very effective!
AVG Free Edition
Download sites:
Provides:
- Anti-Malware
- Link Scanning for Web Surfing
- Automatic Update
- Resident Shield
- Virus Vault
AVIRA Antivir Personal
Download sites:
Provides:
- Extensive malware recognition of viruses, trojans, backdoor programs and worms
- Automatic incremental updates
- Virus Guard real time monitoring
- Virus protection against known and unknown threats
- Quarantine
Note: You can only use antivirus one at a time, so choose only one to install.