When I go to "My Computer" or "Windows Explorer" my Fixed drives do not show/display. When I go to Computer Management - all four drives show as active, but with no drive letter assigned. Disk '0' is partitioned into 'C', 'D', and 'G'. Disk '1' is 'H'. This just happened yesterday, up until then everything was fine. I did not do any installs or deletions, or make any changes to my setups. If I enter a drive letter in the address bar of 'Windows Explorer' the drive(s) display. I have tried changing/adding a drive letter, but the letters 'C', 'D', 'G', and 'H' do not show as available.Please Help.Thank you