Many people may "get" that pop up when their windows Starting.

Why that happens?
Well...
That happen cause, windows XP trying to load a 32bit Application when the version of Ms Windows XP is 16Bit.

How can i fix it?
It's really simple. And they are several ways to fix it.
1. Open your startup and delete from there, WINDOWXP.exe
Restart your system after that.
(If you do that, The pop up will stop appear when you start your Windows XP)
2. Uninstall all the 32bit programs from your computer and try to find the same ones in 16bit versions. (For those that using 16Bit Windows XP)

If your problem Continues Repost here.

Cypher. A.K.A Static

Hi Ub3rCyph3r,

Your file to delete "WINDOWXP.exe" was probably a Trojan
In most cases this NTVDM errors are caused by Trojans on a users system
Sadly the names of these Trojans can vary from system to system.
It is wisest to do a full spyware scan using many freely available products on the web. Also, always confirm your Antivirus is updated and a full scan is also completed with that.

MS Help and Support have also a "Troubleshooting NTVDM and WOW Startup Errors" That would be wise to check out.

There is also an article about installing 16Bit programs on Windows Xp h e r e

I wouldn't recommend doing this. As you won't have any programs left I'd suspect.
Also for those that using 16Bit Windows Xp don't exist. As Windows Xp is only 32 or 64 Bit. 16Bit was used in the old Dos days and in Windows 3.1