I even had one come in last week, Windows 7 Ult. Had a XP COA, running D7, told me it was a technet code. Client went somewhere else a few months ago, and ordered and paid for Win 7 Home Prem. Had a virus on the machine, the 'tech' (local guy) who installed it, couldn't remove it, so told him to come to me.
When seeing the XP coa, and the Win 7 ult I contacted my client to see what was going on. It was then, I was told about the win 7 install. I asked have you got the installation cd?, Nope, I wasn't given one.
So I explained, that when ever you purchase a new version of windows, and install it, you always get a installation cd/dvd and a COA. That way, you know that Windows has correctly been upgraded, and he should ask the 'tech' for these. Knowing that the guy would not have them, I waited on the call, and backed up my clients data.
2 hours later phone goes again, and i'm asked will I order and install what he had originally wanted, he was going to get his money back off 'tech'. I did say to him that the cost of this repair would be in the region of £160.00, and it would be better put towards a replacement machine instead. And for another couple of £00, he would have a ferrari, compared to the robin reliant he currently has.
Again he was not informed of this from 'tech'. He gave me carte blanche to do what ever I felt required. With a limit of £400.00, I built him a decent machine, gave him the install media, and my client was ecstatic.
Just goes to show, that informing your clients of what is legal, and what should be done, has gained me another client, who I am confident will recommend me to others. Not all clients want the cheapest option.