a: and CD access denied

OS XP PRO, For both my floppy and CD I get error message Access denied.
I log on as administrator, no password.Device manager shows both drives as enabled. Reloaded drivers. In safe mode I can access floppy and recover its data. Talked aver an hour with MS support, dug into REG tried all we know.
Have another HD with older OS created on same machine,BOTH DRIVES WORK.

desperate