What is the Difference between Win 7 Home premium and "Home Premium w/SP1 64-bit-System Builder License and Media"? The builder is much much cheaper than the retail. What are the differences? Can the builder pack be upgraded to pro with one of those upgrades home to pro upgrades?
System Builder or OEM is locked to the motherboard of the 1st system it is installed on.
ie. not meant to be transferred from PC to PC. Also the vendor of the PC with the OEM licence is responsible for for the software (Advice etc.) The retail version is more flexible, can be installed on any machine as long as only one at a time. Microsoft provide the backup for the software. OEM software can be upgraded.
Definitive answer regarding OEM http://prntscr.com/9537y
Well, as you are unlikely to be able to upgrade your motherboard when it becomes obsolete, with Retail you could transfer to another custom laptop/desktop whatever. OEM could not be transferred. On the other hand, if you're confident that your lappy will last for several years and by that time you can't do without Win 8/9/10, then save money with the OEM.