oem stuff is supposed to be sold to system builders in bulk package, the manufacturers may just give them one copy of manual and driver, the system builders make their own all-in-one manual and driver for their house-built system. many computer vendors sell such oem stuff to end-users beside selling house-built system. most manufacturers don't provide warranty to end-user on such oem stuff, only few exceptions - bare harddisk, ati made oem vga card, diamond oem vga card, etc do have same warranty as retail version. every vendors do give their own warranty on oem stuff, you can see that all oem stuff have a dated sticker, that's how a vendor determines if it's sold by them and when's it sold.