[dba-Tech] Vista question

A friend recently purchased a new laptop and when asked if she could convert 
to Windows XP, the salesperson told her no -- didn't offer her the available 
license, just told her no. She asked if she could reformat and install it 
herself and he said no because Vista machines have an embedded code that 
inhibits Windows XP. Anyone heard of this embedded code? I think it's a 
total lie, but thought I'd ask -- nothing MS did would surprise me anymore.

Susan H.