Policy varies with OEM
I just recently bought a lowend Toshiba laptop and the EULA for this machine stated that the return policy was (and I quote):
"By using the software, you accept these terms. If you do not accept them, do not use the software. Instead, contact the manufacturer or installer to determine its return policy. You must comply with that policy, which might limit your rights or require you to return the entire system on which the software is installed."
Toshiba's policy on not accepting the EULA is:
"...TAIS DOES NOT ACCEPT THE RETURN OF COMPONENT PARTS, OR BUNDLED SOFTWARE, WHICH HAVE BEEN REMOVED FROM THE TAIS HARDWARE PRODUCT. PRO-RATA REFUNDS ON INDIVIDUAL PC COMPONENTS, OR BUNDLED SOFTWARE, INCLUDING THE OPERATING SYSTEM, WILL NOT BE GRANTED. "
The loophole has closed.