Due to differences in encoding and storage of the GUID/UUID between the BIOS and Windows, some of the data in the GUID stream is transposed when queried by SCCM. See examples below:
Figure 1: PXE GUID Readout
Figure 2: SCCM UUID Readout
Figure 3: Convert the GUID to the UUID
Most computers fall into this transposition algorithm; use this if entering the UUID manually into SCCM is wanted.