Maximum PC

I just upgraded from Windows XP Pro to Windows 7 Pro 32-bit. I'm running an Intel i7 920 with 6GB of RAM. My question is that on the Computer, it says I have 6GB of RAM only 2.49 of it is usable. The reason why I upgraded in the first place is that I wanted the OS to use more of the RAM because XP limited it by less than half.

Do I need to buy the 65-bit version of Windows 7 Pro in order to use the other 3.5 GB my PC isn't using?

Any 32-bit OS is limited to approximately 4GB of RAM seen.
A 64-bit OS is needed to access more than that.
http://msdn.microsoft.com/en-us/library ... 85%29.aspx

how come it only says 2.49?

Also, is there a downside to getting the 64 bit version other than the price?

Other devices use the memory address space.

You can address 2^32 locations.

DMA for hard drives, shared video memory, etc. All of that comes out of the 4GB limit under 32 GB.

your video ram is most likely g taking out the 1.5gb while 2gb is being wasted/not ultilized in a 32bit environment. Also, technically, XP can only see 3.25 or 3.5gb total.

This is what I have right now. 4GB of RAM installed, with 128MB for integrated video, and System Properties says I have 3.5GB installed.
http://en.wikipedia.org/wiki/3_GB_barrier

The only downside may be that some drivers aren't available in 64-bit form, but that's rare these days, AFAIK.

Looks like I'm gonna have to get a 64 bit Windows 7

why did you upgrade to win7 32bit anyhow? just wonderin.

Yep. Can I upgrade to 64 bit without reformatting?

There really is no upgrade path of going from 32 to 64 without doing a clean install

The migration tool was supposed to deal with this, but I have no idea if that would even work in this case.

What exactly are you trying to save?

I have a whoooole lotta programs installed and reinstalling them one by one will be a major pain in the butt, including WoW which is like 40GB alone with the patches. Steam, games, add ons, etc... it's gonna be a pain

Will 32-bit programs work with windows 7 64-bit? I have an old photshop copy that came out years ago that I want to install, as well as older games and programs designed to work with 32 bit.

Most will, yes.
Win7 x64 runs 32-bit programs in an emulation layer (MS calls it "Windows on Windows" (or, WOW64.)
And, generally, if it runs on Win7 x86, it'll run on Win7 x64. But, there are always expections. When in doubt, check with the software vendor.