What's "Invalid startup directory, please check your pif file"?

Anytime I try to start up QBasic 4.5 on Windows XP, I get an error stating "Invalid startup directory, please check your pif file. Choose 'Close' to terminate the application." I know that this is a 16bit MS-DOS Subsystem, but this is the only program I am having trouble with. I recently upgraded to WinXP Pro, and needless to say, I was quite surprised when I couldn't write my programs anymore.

Boy... now there's a blast from the past. QBasic has a long history dating back to the days of MS-DOS. QBasic was the free Basic programming language interpreter that was included with MS-DOS, and eventually Windows, though it appears to have vanished from Windows XP, if not from earlier versions.

I feel a personal connection to QBasic. Why? I worked on it!

First, your question: ".PIF" files were the way that older versions of Windows kept track of the settings for some applications. Each application, say QBasic.exe, would have a corresponding PIF file, such as QBasic.pif.

"QBasic was the free Basic programming language interpreter that was included with MS-DOS"

In Windows XP, I believe it's safe to simply remove the QBasic.pif file. Try renaming it first, and seeing if that resolves your problem. You can also try right-clicking on the PIF file in Windows Explorer, selecting Properties, and changing the startup directory, that your error message is complaining about.

I dug up an old copy of QBasic and fired it up, without a .PIF file, on my Windows XP system:

QBasic

Like I said it brings back memories. While at Microsoft I worked on the on-line help technology used in QBasic's predecessor, QuickBasic, several other products, and in QBasic. Need proof? In a command shell, Type the on-line help file qbasic.hlp. The first two bytes are the "signature" that define what kind of a file this is. The signature for character mode help files? My initials: LN.

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