SYMPTOMS
When you try to run an MS-DOS command from a command prompt at the root folder of your C drive, you may receive one of the following error messages:
Incorrect Dos Version
-or-
Error Starting Program. A required .DLL file, ULIB.DLL, was not found.
CAUSE
This behavior can occur if there is an MS-DOS version of the command you are trying to run in the root folder of your C drive. When you try to run an MS-DOS command from a command prompt at the root folder of your C drive, Windows looks for the command in the root folder before it looks for the command in your path.
RESOLUTION
To resolve this issue, rename the MS-DOS command in the root folder of your C drive. To do so, use the following steps:
Click Start, point to Find, and then click Files Or Folders.
In the Named box, type the name of the MS-DOS command you want to run, and then click Find Now.
Right-click the file (after you verify it is in the root folder of your C drive), and then click Rename.
Rename the file to a .old extension, and then press ENTER.
Quit the Find Files Or Folders tool.