Windows Vista OEM vs. Retail

[stargate125645]

biz has the networking tools and user control and the same hardware restrictions as ulti, but has no media center or bitlocker so its the cleanest out of the box and there is like a +$10 difference from HP

I am unfamiliar with bitlocker... Upon looking up information about it, it seems that one can disable it so is it a nuissance even when disabled? Also, does no Media Center mean no Windows Media Player? That is currently what I use to play my music collection, and I don't want to have to buy it separately.

By HP do you mean Hewlit-Packard? Is there some particular reason I should buy Vista 64-bit from HP? On newegg Vista Business is $40 cheaper (Business = $140, Ultimate = $180).