I am running XP Home SP3 fully patched. I have some old software originally written for Window 3.1 that has continued to work quite happliy until now. I know it worked on 18 September as that is when the last usage of it was. Since then I have applied all the software patches (15). Now when I click on one of these applications, I get the hourglass for a second, then nothing. I have tried all the compatibility options, but none work. I have to assume that M$ have done something, but what? And how can I get these applications working again?

what app is it

It's a very old version of Borland's TurboC compiler - 3.1 if I remember correctly, together with an application compiled with it. I am (slowly) in the process of converting it to Visual C++ but have still a long way to go, so I need the original to keep working until then.

Hello Norman. I think you should upgrade to the newest version of Borland's Turbo C. The older version was not meant to be run on Windows XP and therefore, has started to dysfunction. Please download the newer version and replace that with the older one. Do you still experience the problem?

Hope that helps.

-- Broledh

Unfortunately, there is no conversion utility between version 3 and anything higher. That's why I was continuing to use it. I am slowly learning Visual C++ to convert it to, so why do a second conversion if I don't have to.
The whole point is that it did work on XP until mid September and now has stopped. If I can find out why I could at least pull that fix (temporarily) until I can get the new version working.

Well, you must be lucky to have it running on Windows XP - Service Pack 2. When the program was released, Windows XP was not released or even thought of, so the creators didn't make it for Windows XP. After you upgraded to Windows XP Service Pack 3, the program might have started to dysfunction due to one of the updates included in Service Pack 3. Service Pack 3 contains hundreds of updates more than its predecessors and therefore determining the cause of the problem would be an exhausting task.

If you want to continue using the program, then your best bet is to revert back to Windows XP Service Pack 2 when you were able to run the program flawlessly.

Please read the below article to learn how to uninstall Service Pack 3 from your computer.

How to remove Windows XP Service Pack 3 from your computer

Hope that helps.

-- Broledh

The point is that it worked perfectly with SP3 until mid September and now doesn't. If I could find which fix did that I could uninstall it until I can get the replacement program up and running!

OK, so in this case, see if a system restore is able to resolve your problem or not.

Use System Restore to Undo Changes if Problems Occur

Let us know how it goes though. Good Luck.

-- Broledh

Would that it were that easy. We are talking about two months ago, and mine don't go back that far.
As a point of interest, I have run Process Explorer and it showed an access to ntvdm.exe, which is the 16-bit Virtual Machine, which is what the software is. It went green then red, and nothing else. I suspect that one of the recent fixes may have disabled it. Can anyone shed any light on a possible suspect?

the dos 16 bit layer doesnt exist at all on server 2003 or xp pro x64, and therefore i assume vista. So perhaps it is time to upgrade