My bet is corrupted windows installation, software installed with bad or corrupted Upper or Lower Filter drivers or some sort of driver conflict.
Is the drive visible under in the Windows Device Manager when it's not working?
If yes then open the registry editor (regedit.exe) and find this key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e965-e325-11ce-bfc1-08002be10318}
Select in on the left side of the registry editor and look on the right side. Do you see any values named "Upperfilters" or "Lowerfilters"? If yes let me know what their value is.
EDIT: Do not touch anything in the registry other than what I am telling you. If you edit/delete anything in the registry without knowing what you are doing you risk damaging your Windows installation.