If what is occurring is the result of a SUBST command being executed in some batch/command/script file (.BAT or .CMD), there are several places where this could be happening automatically at startup/login in Windows XP. If this behavior isn't the result of malware, it might be best to locate where it is happening, and then try to determine if it is necessary or not. A few of the possibilities are:Start, Control Panel, Scheduled Tasks:
Among the other scheduling choices, a scheduled task can be set to run "At System Startup" or "At Logon". If you have any such task (right-click the task, select Properties
, then the Schedule
tab), check the file that is being run (using the Task
tab):http://img238.imageshack.us/img238/3608/subsdauv4.pngStart, Control Panel, Administrative Tools, Computer Management:
In the left pane, navigate down to Computer Management (Local), System Tools, Local Users and Groups, Users
. The right pane should show all users. Right-click the account you normally use, select Properties
, then click the Profile
tab. In the User profile
area, see if there is a logon script file specified for that user in the Logon script:
If you find a .BAT or .CMD file in any of these places, you can open that file with Notepad to see what commands are being executed.
In your original post, you didn't mention whether you just noticed this behavior (and it may actually have been occurring for quite some time), or whether it really did just start happening. If it did just start happening, is there any software that you recently installed?
If you reboot your computer and open "My Computer" immediately (without doing anything else before), do both the C: and D: drives appear in the display? If the D: drive isn't listed, it might be that there is some other program you run after booting the computer that is causing this behavior.