I recently ran Microsoft Security Essentials and it detected and removed about 12 exploits and trojans related to crimepack.class. Since I've read you can never be sure that a virus is totally removed, I would like to reformat the hard drive and do a clean install of windows 7. My problem is, I have an acer aspire and when I called their tech support they said I could only get the reinstall Cd's for $20, otherwise I would have to use a hidden partition on the hard drive to reinstall windows (when I bought the computer new, it was NOT shipped with the windows CD's). I've read that using the hidden partition to reinstall windows is not as secure as reformatting, So, if this is the case, do I have to bite the bullet and pay them to send me the CD's or do I have any other options? Thanks!