About windows oem answer!

Q: What is oem? After installing windows 7 oem can always format it? Can put the old computer (windows 7 oem) installed in the new computer? If the hardware is broken than to get a new one! Such as (hard disk, processor, or network card) need to re-install (windows) it?
A: OEM - Original Equipment Manufacturer is to follow the version shipped with the machine, not retail. OEM software can only be a new installation, not from the old operating system upgrade. If you buy a brand of notebook computer or computer software will be random. Unlike the retail version of the beautiful packaging, usually only one CD-ROM and manual (power of attorney). This system is usually less driven, and the current OEM version on the CD can give you small installation, is the general recovery disk or disk image