Ok,
I found this at Dell's site for a Chipset update for your Dell Dimension e510. It says that it's needed to keep BIOS, etc.. up to date. It is for the 64 bit Vista. I would recommend running this & then run the BIOS update. If it still doesn't work, you may try doing it in SAFE MODE in case something is interfering with it.
Here's the link for (Motherboard drivers) Chipset :
http://support.us.dell.com/support/downloads/download.aspx?c=us&l=en&s=gen&releaseid=R140595&formatcnt=1&libid=0&fileid=187623
Here's the link for the BIOS I found. (probaly the same that you are trying) :
I noticed that Dell use to have A06 as the newest version but pulled it &
only has the A05 now.
http://support.us.dell.com/support/downloads/download.aspx?c=us&l=en&s=gen&releaseid=R121641&formatcnt=1&libid=0&fileid=161979
Hope this works,
Shawn