Q. How to Change Default Drive in dos?
To modify a default drive type the new drive letter followed by colon (:) and then press Enter. For example, if the default drive is A and you type C: and press Enter, DOS selects drive C: as the default drive. DOS verify this by changing the prompt to C:\> or a similar message. If you enter a drive letter that does not exists in your PC, DOS displays a message "Invalid Drive Specification".
When you choose a floppy drive as the default drive, make sure that there is a diskette is inserted in that drive. Otherwise, DOS gives the following message:
"Not ready reading drive A
Abort, Retrieve, Fail ?
If you get this message, insert a diskette in the floppy drive and then press "r" to Retrieve.