Terry, I've never ran into this problem before with NT 4.0. If you are not adding any extrenal resources to your program other than your EXE (ie. OCX'S, etc.,) you should be able to just copy the EXE file (overriding the older one) without having to perform a new install.

In addition, if you are still getting the same error, you may want to uninstall your application and re-install it with the new version. (save your data if your install overwrites it).

I would also recomment that you re-apply your NT SP3 or SP4 before and after you app install.