Backup and Recovery, v. 2010, updated 11844.0001. Windows XP home. Main page shows that file system is invalid and that drive c:\ is invalid. What does this mean? How to correct? Drive info includes disk size, reported 149 GB; it is actually 160 GB. Windows chkdsk does not report any problem. The option to "check disk integrity is grayed out. No action taken. No log available. Links do not appear in Start Menu. What to do?