While whatever wizrulez wrote, he copied it from here
Now to the thread.
Dos applications run slow on NT machine because (as already stated) they are 16 bit applications and XP being a 32 bit OS runs them under a virtual machine (thats your NTVDM.exe).
This 16 bit emulation works like this : There are actually two process that creates this emulation : wowexec.exe and ntvdm.exe ..
Wowexec : Window16 on Window32 Exec : Converts the 16 bit api to 32 bit api
NTVdm : NT Virtual Dos machine : Emulates the Dos operating system and handles all the api calls.
This emulation and translation takes some time and hence you feel that the program is running slow.
Possible solution : Right click on the exe of the file and select properties.
Click on Comatability tab. Select Run this program under comatibilty for Windows 98 . Apply .. Try now ..
How I know all this ^^ ? I am trying to make some legacy applications run on NT architecture these days .. experience pays ..