Replaced MOBO on Dell 5510 BIOS sticker on MOBO says A05, system in still has BIOS of A07

I replaced the mobo on my Dell 5510. Purchased from Dell. Sticker on mobo says BIOS ver A05. About every other day I get blue screen and physical dump of memory. My system info says my BIOS ver is A07. How do I go about changing BIOS? Is it as simple as pulling battery for 15 seconds? Some have offered this suggestion but I get a little worried at "friends" advice.
 
Removing the battery won't change the BIOS version. You need to download the version you require from the Dell site. From Windows you "flash" the BIOS. Take your time preparing for this. If anything goes wrong you will wreck your motherboard.
 
Back