spybot doesn't convince me at all. Remember that professional keyloggers has the option to "melt" the server in your system (%windir%/sysdir) therefore if the server has been named as an important component of windows the antivirus/antimalware won't delete it .
The best antivirus i seen is AVIRA home edition (yes free),install it and run a full scan. Also i recommend having a good firewall.
