Although I'm (technically) an MS System Builder, I'd never heard of "DSP". As Stash notes, it stands for "Delivery Service Partner". The term seems to be more commonly used in Europe and Asia.
I found
this site that describes the difference between and "DSP" and "non-DSP" OEM software. It says that
DSP is the "generic" version (not labeled by a particular system builder). So, if you buy the typical generic "OEM" software from Newegg.com, you're buying "DSP" (non-labelled) software, that can be used on any new PC.
Conversely, non-DSP software would be BRANDED OEM software, intended for distribution only on a name-brand PC such as a Dell.
What is OEM and DSP software?
OEM means ?Original Equipment Manufacturer? and normally with a computer manufacturer?s name stamped on it. DSP means ?Delivery Service Partner?. DSP software is similar to OEM software however there is NO manufacturer?s name stamped on the CD 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. The software itself contains the same programs as the Retail Box version, except the Retail Box version normally comes with a small printed manual.
Since DSP and OEM software is typically sold to more advanced users, system builders and computer consultants, there is no technical support provided by the software manufacturer. However, because of the substantial support savings to the manufacturer the DSP and OEM versions are offered for sale at a significantly lower price. Also, this CD is bootable and contains software wizard that enable you to complete a full installation including hard drive formatting and partitioning, upgrade only, and system check to determine if your system is compatible and functioning correctly for this new version.