How to fix not enough drive letters issue

LASTDRIVE= line not set up properly or not defined

Verify LASTDRIVE= line is present in your config.sys file. If this line is present, ensure the drive letter specified is greater than the amount of drive letters.

For example, the line could read:

LASTDRIVE=Z

dblspace.ini is missing or corrupt

If double space or disk compression has been used on the computer, verify on the startup disk (drive C) that the dblspace.ini file contains the following two lines.

MaxRemoveDrives=2
LastDrive=F