Running multiple instances of Adobe Reader

I have a user that wants to open a new instance of Reader whenever he opens a PDF from within Windows Explorer (double-click the file). I have found that if I go through Start –> Run, that I can use “AcroRd32.exe /n”, but I can not seem to get this to work within the file associations in Windows.

This is Acrobat Reader 7.0.9 on WinXP SP2 machine.

I would appreciate any guidance anyone can offer.