Not really, there is no need to use pure 64 bit os to take advantage of more rams, windows 7 32 bit can optimise more then 4GB ram using PAE technology (http://en.wikipedia.org/wiki/Physical_Address_Extension), PAE are somewhat the same like our 32bit processor that support 64bit code (by extention). Your motherbord/bios need to support PAE and remaping memory address. The other thing you need are the kernel patch to remove 3.xgb ram limit by microsoft, those who are like me that have 4GB ram but windows 7 32bit only see 3.2GB ram usable, can use the patch to fully utilized full 4GB ram, just make sure your motherboard bios detect the correct full 4GB or 8GB of your system ram.

Here is the patch, its been made my russian and russian language.

http://www.filestube.com/a8ac06048c61792003ea/go.html

if you cannot download from there just search in google, the file name is 4GB-7600.RTM.x86.04.08.2009.exe

When the program open, it just have one button, just click it and after a while it will prompt some black screen to remove the watermark, just press y and it will reboot your windows 7. After that you will have 2 windows boot option and you also can select the old win 7 kernel (just in case), just select the ">128 GB memory" and load your windows 7, check the information page for the ram used. To edit the boot option i recommend program name EasyBCD, you can edit some option of the windows boot manager like default boot option and auto time timer (10 second min).

After this some of you might still have a watermark of windows test mode in the right bottom desktop, means mcbuider need to be run again, open cmd in run box then type mcbuilder.exe and enter, this might take a while, after that reboot your system and the watermark will be gone.

I tested it out my self with windows 7 ultimate, and its work, I got full 4GB and even try add another 1 stick of 2gb more, so total would be 6gb of rams in windows 7 32bit.

Hope I can help you all with this.

My windows 7 32-bit with 6GB of RAMS.