This is a known problem which can occur in Windows. The problem is usually caused by having Drive C assigned to a device with removable media. If you have that situation then either put media in Drive C or reassign the device to another letter.

There are instructions for reassigning the device to another letter here:

• "There Is No Disk in the Drive. Please Insert a Disk into Drive \Device\harddisk\Dr1" Error Message When You Start Your Computer http://support.microsoft.com/default.aspx?scid=kb;en-us;330137