I guess you have read the other "Guides" regarding OEM licences. You should really read the Microsofts own view on this.

The previous guide is partially correct in that the label on the OEM product does say

            "This OEM software may not be delivered unless accompanied by the required hardware under the Microsoft OEM system builder license located at  w ww.microsoft.com/oem/sblicense . End user support is the responsibility of the installer of this software." ( remove the space in www)

If you follow this weblink you can download the agreement    h ttp://oem.microsoft.com/downloads/Public/sblicense/English_SB_License.pdf  (remove the space in http)

If you read the first paragraph it clearly states:-

       ".....If you do not open this package, you may distribute it to another system builder. “System builder” means an original equipment manufacturer, or an assembler, reassembler, or installer of software on computer systems."

So make your own mind up to whether you are an assembler of PC's, then you may purchase an OEM licence without hardware or breaking the law.

Ebay are at odds with this view so you will have to make up your own mind as to wether you chance selling OEM software.

Have a nice day