Yes, the 32bit will not see the full four gigs, it's even mentioned on the configuration page when you're putting the PC together.

 

Try searching these forums for "vista 3 gigs" you'll have more material to read then you've ever wanted on the subject.

Dells advisory about 4 gigs

http://configure.us.dell.com/dellstore/config.aspx?c=us&cs=19&l=en&oc=DDCWDI1&s=dhs
What it reads below…..

" Systems configured with 4GB memory or more: The total amount of available memory will be less than 4GB. The amount less depends on the actual system configuration ".



Only sure way to address the full 4 gigs of memory is to get the 64 bit version of the operating system. Once you do, than you will have to download the Microsoft Hotfix and have it waiting some where on the desktop for later install.

You will than turn off the system, remove two sticks of memory, leaving you with 2 Gb total. Boot back up, install the Hotfix, than turn off the system and reinstall the other 2 gb of memory into the proper slots. Boot back up, now you are done.

Hotfix download link

http://support.microsoft.com/kb/929777  

Links takes you to a site that has a good run down on addressing memory

http://www.hardforum.com/showthread.php?t=1035670
http://evga.com/forums/tm.asp?m=85830
http://support.dell.com/support/topics/global.aspx/support/dsn/en/document?c=us&cs=19&docid=BF4C8393BFC74A83B9EC318630B9CE7D  
http://msdn2.microsoft.com/en-gb/library/aa366778.aspx

If you want the 64 bit version of the operating system, than you can at anytime, purchase the OEM Vista 64 bit version from most retail computer stores or online, which does not cost as much as the Retail version, but it’s only good of one system, and no tech support either.
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