here is what I have found from
Buy Cheap Software
DSP means ?Delivery Service Partner?. OEM means ?Original Equipment Manufacturer? and normally would have the hardware manufacturer?s name stamped on it.
DSP software is similar to OEM software however there is no manufacturer?s name stamped on the manual or printed on the license.
DSP software is more generic and OEM software is sold directly to the computer manufacturer. Thus the distribution channel is different for DSP.
DSP software is distributed for smaller system integrators and system builder hobbyists for ?clone? or no-name computers.
Like OEM versions, DSP versions often come with only an electronic help manual, which is built-in to the software or a small getting-started manual.
The software itself contains the same programs as the Retail Box version, except the Retail Box version normally comes with a small printed manual.
Both OEM and DSP Microsoft software include a COA, which is a Certificate Of Authenticity label or sticker from the manufacturer.
Hope this helps.
Shamrock