i am only guessing here, but it would be one of your startup pgms looking to use a drive that it is configured to expect to be there, but which is in fact not. Could be this one:
O4 - HKCU\..\Run: [Creative Detector] H:\Program Files\Creative\MediaSource\Detector\CTDetect.exe /R
.work your way thru the list of startups [O4 entries] and check which ones use drive media, and are they setup correctly. Some could be removed with no problems to you.