I forgot one other option. Sorry about that. The other option is to run Windows XP Mode if
you have Windows 7 Professional and a CPU that can do virtualization. If so, you could then install it under that and you should be good to go. Just go here to get all you need to install it -> http://www.microsoft.com/windows/virtual-pc/download.aspx
If you don't have Windows 7 Professional or your CPU cannot do virtualization, then you could download either VMWare Player, Virtual PC 2007 or VirtualBox (all are free) but it requires that you have a valid copy of Windows XP to install.
Either way will provide you with a virtual machine of Windows XP to run within Windows 7 and then you can install your program under that virtual machine and you should be good to go!