How to designate Office 2003 to be default to open documents

I am stuck with a complicated problem but will try to explain here as simple as I can. I am having a Windows XP based desktop computer with all Windows Updates and pretty good config. It was running with Office 2003 but as our clients files use to be in both Office 2003 as well as 2007 formats, I bought a Office 2007 as well and installed on the same computer. Note, I dint overwritten my existing office, but installed it separately.

Now the problem is once I opened word 2007 and Excel 2007, all my office programs use to open with Office 2007 by default and not with 2003. I even tried to corrected the associations for .DOC .PPT and .XLS to point to executable files by going to Explorer > Tools > Folder Option but that is for no success. So finally I uninstalled both version and reinstalled them individually in separate folders as follows:
Office Explorer > Tools > Folder Option
Office 2007 to C:\Program Files\MS Office 2007

Doing this also dint helped. Can anyone tell me how can I make Office 2003 as a default for MS Word, Excel and PowerPoint documents ?

First of all I don’t think there was any need to change the installation path if you have had installed both of them in separate folders. But you must know that whenever you install any latest version of a particular software all files (no matter compatible to old version) will open with the latest version itself.

The only thing you can do here is instead of double clicking files to opne, you should launch Office Excel Word or powerpoint 2003 first and than browser and select files. This will help you opening them in Office 2003.