test app on 64bit windows

I don't have 64bit windows, and i have to develop app for 64bit windows.

I have downloaded and installed virtual pc

i develop on windows xp 32bit, vista 32bit and win7 32bit

How to i develop a 32bit compatable application?

[EDIT] Am develop开发者_StackOverflow社区ing using visual studio 6 & 2005, Borland c++ 7. And i havent seen 64bit versions of this softwares

In order to run a 64-bit application, you will need a 64-bit OS and 64-bit hardware. You can't run a 64-bit guest on a host with 32-bit hardware.

You can build a 64-bit application with Visual Studio 2005. I do not know about other IDE's you mention. If I remember correctly, you have to choose to install the 64-bit tools when installing VS2005. I seem to recall that they do not get installed by default (but memory may be failing me). Once the 64-bit application is built, though, you cannot run it on the 32-bit machine.