I search everywhre, but everywhere the tell another story (some say win7 32 has 3GB limit, some say 4GB)...So I want this to be clear:I have a machine (running WinXP Pro (default), it has 4GB RAM (XP does see 3GB, I know for sure that XP32 only supports 3GB)So I want to upgrade to Windows 7...Does Windows 7 (Ultimate) 32-bit support my 4GB RAM, or do I need to get a 64-bit version?

Windows 7 32-bit works the same as XP 32-bit with respect to RAM recognition. No difference. It will see 4GB, but only address 3.XGB. A 64-bit OS will see and address your 4GB or more of RAM.

Alright, thank you very mutch (both)!If I look at the factory website, it says it should be able to take 8GB, so I guess that won't be a problem. But now I know for sure that I have to install a 64-bit Win7... Thanks!

Hello SparkyRih, According to your description, please understand that the question is not caused by the Windows 7 product itself. Since you installed 32-bit OS, the system could only recognize 3.3GB although we find the total RAM is shown as 4GB in BIOS. If you need full use of 4GB ram, you should install 64-bit product on the computer. For more information on this subject, please refer to the following webpage. The 4GB Windows Memory Limit: What does it really mean? For your current situation, please purchase the Windows 7 64-bit OS; format the HDD and do a clean-install on the computer. Thanks for your time and understanding! Good Luck! Andy

Here are your answers: http://msdn.microsoft.com/en-us/library/aa366778(VS.85).aspx#physical_memory_limits_windows_7 Now my questions is...If I put 8gb in my laptop (knowing that Windows 7 will only support 4gb, will my hard drive start heavy file paging like Vista did? Or will it gently ignore the extra ram?

Here are your answers: http://msdn.microsoft.com/en-us/library/aa366778(VS.85).aspx#physical_memory_limits_windows_7 Now my questions is...If I put 8gb in my laptop (knowing that Windows 7 will only support 4gb, will my hard drive start heavy file paging like Vista did? Or will it gently ignore the extra ram? 32 bits OSs will only address 4gb memory whatever the OS is. Why would you want to put 8gb RAM if you use a 32 bits OS? Use 64 OS with more than 4 gb RAM.I've installed 8 gb RAM with Win7 Home Premium 64 bits and it's lightning fast. Use 64 bits OS if you want more than 4 gb but make sure your machine is 64 bits ready and you have all the drivers for your hardware.When you buy Retail (boxed) versions of Win7 (Full or Upgrade), both DVDs are included (32 and 64 bits), for OEM versions, ask the computer dealer.

check this plz,officail saying http://msdn.microsoft.com/en-us/library/aa366778(VS.85).aspx

32 bits OSs will only address 4gb memory whatever the OS is. That's not quit right. Windows Server 2008 Datacenter 32 Bit supports up to 64 Gb RAM. The here: Physical memory limits windows server 2008

If we have 4GB of RAM, is there any advantage to using 64bit Win7? I have limited hard drive space and noticed that 64bit Win7 Ultimate requires about 20GB of additional hard drive space Am I correct in assuming that it comes down to...is it worth sacrificing ~20GB hard drive space for an addtional 0.7GB in RAM space?

If we have 4GB of RAM, is there any advantage to using 64bit Win7? I have limited hard drive space and noticed that 64bit Win7 Ultimate requires about 20GB of additional hard drive space Am I correct in assuming that it comes down to...is it worth sacrificing ~20GB hard drive space for an addtional 0.7GB in RAM space? That is not correct. According to Microsoft, Windows 7 32 bit requires 16 gb of space and Windows 7 64 bit requires 20 gb of space. It's only a 4 gb difference between the 2. If your computer can run a 64 bit operating system I'd put that on just in case you decide at some point to add more ram or have some 64 bit programs to install.

That's what Microsoft quotes, but I've done both 32bit and 64bit installs and after you do all the SP1 and other updates, 64bit ends up being about 20gb more hard drive space. Please test this on your machine and let us know your results as well. It's definitely not 4gb more like Microsoft quotes, in my experience.t1138