(I have rectified my answer. To clarify: every process gets 2 GB of virtual address space. All processes combined can't exceed 4 GB of physical memory)
Actually, yes. There are many misconceptions about the memory limit in 32-bit Windows OSes.
First of all, when I say RAM, this includes every kind of RAM. So not just regular, but also your video RAM. Only physical memory though, not swap/paging.
The maximum available amount of RAM per process for a 32-bit OS is 2 GB. If you have a 64-bit OS, a 32-bit process can allocate up to 4 GB.
Additionally, the entire OS can only address 4 GB for every process combined, while 64-bit OSes can allocate 8 TB.
Also interesting is that this limit adds up to the paged pool. This means that a 32-bit OS cannot use more than 4 GB total, which means 6 GB for all applications including virtual memory. Of course, this has nothing to do with RAM, because the other 2 GB would be stored in the paging file, limited to your hard-drive's speed.
For more information, see Memory Limits for Windows Releases.