VB6 Troubles with Drive Drop Down List: 68 error Drive not accessible

This one is wild. I haven't got a clue why it will not work.

I'm using VB6 & SP6 with Windows 7

I created a little test program that has one Drive box, one Directory box, one Command button and nothing else.

When I execute the program, I can set the Drive box to any of the drives on the computer. In addition to the C hard drive,
I have one CD/DVD drive, two external hard drives and one flash drive.

In the Drive1_Change event, I set the directory box to the Drive as in:
Dir1.Path=Drive1.Drive

That all works as it should.

BUT, if I set the Drive1.Drive to an external drive in the Form_Load procedure, it gives me a 68 error Drive not accessible!
The statement is:

Drive1.drive="F:" where F is an external hard drive.

It works fine if the drive is the C: drive not not an external drive.

I have used setting a Drive box in code in a large program and it worked for years (like, at least 10 years).
I have not changed any of the code in this area. Now, it gives me the 68 error!

Other programs, like Excel and Word, do not have any trouble accessing the external drives.

Any help and ideas are greatly appreciated!

-Peter