My computer here at work has 4GB working off of 32 bit windows XP.  I was at a computer store over the weekend and the sales guy said 32bit systems won't recognize/use any RAM over 2GB.  Is this true?  My computer seems to work better now with the added RAM. 

its more like a little over 3GB of ram, I am running with 4GB of ram on a 32 bit os and my comp recognizes only 3.43....

My computer has 4 gigs also and windows reconizes 3.5. I think it is windows that does not reconize the correct amount, because if i go into the system setup it shows that I have 4 gigs. All three of us show diffrent amounts so it might have something to with the system bios version. I don't know where to get a bios update, probally from the PC vendor I guess.

 its not a windows or bios thing.  It actually get pretty technical.  I can't explain it myself so a google search will.

http://www.brianmadden.com/content/article/The-4GB-Windows-Memory-Limit-What-does-it-really-mean-

In short, you actually need a 64bit system to handle more than 4gb wether it be XP64 or Vista64

Check out these links. http://www.microsoft.com/windowsxp/expertzone/newsgroups/reader.mspx?query=4+gigs&dg=microsoft.public.windowsxp.general&cat=en-us-ms-winxp&lang=en&cr=US&pt=&catlist=B0DE109D-10E1-4C3C-BCC9-8EB7A22FC6A0&dglist=&ptlist=&exp=&sloc=en-us and http://support.microsoft.com/kb/888137. Some of it is the motherboard and bios in what it can handle. It seems that the problem with not showing the correct amount of ram in the systems dialog box came with the upgrade to windows xp service pack 2, but it does reconize the 4 gigs.

Here are two links that explain how Windows uses ram.

 http://blogs.technet.com/markrussinovich/archive/2008/07/21/3092070.aspx

http://msdn.microsoft.com/en-us/library/aa366778.aspx