Vista 32 bit support 4 gigs of ram?

must be since server 2003 does

No. [Or at least the answer is no to what I believe you are asking: Will WinVista 32-bit fully utilize the 4GB of RAM?]

According to various posts, installing 4GB of RAM will work on WinVista 32-bit [as it does on WinXP 32-bit]. However, only about 3-3.4 GB or so (typically 3.2GB or so) will be used by the operating system. The specific amount is dependent upon the hardware configuration. The remainder of the 4GB of installed RAM will be unused (unutilized for anything).

This is evidently due to hardware addressing requirements and what portion is set aside solely for addressing purposes below the 4GB addressing boundary. For example, the mapping of memory on graphics cards is one major cause. (With Win64 and greater-than-32-bit chipsets, evidently no substantial portion of the installed real RAM would be unused.)

Here is another thread that discusses the matter for both WinXP and WinVista:
http://forumz.tomshardware.com/har [...] 13493.html

Here is a link (from that thread) to a more detailed explanation of the limitation in WinXP 32-bit (which is evidently essentially the same limitation for WinVista 32-bit):
http://h20331.www2.hp.com/Hpsub/do [...] 3Nov05.doc

There are also hardware issues. A 32 bit processor can only address 4GB (less any address space used for other purposes). In practice, current 64 bit processors can't actually address 18 exobytes because they don't have 64 physical address lines. But they can address a great deal more than 4 gigabytes