Yes, best to wait until such time as I (hopefully) get the computer back again! In answer to your question though,I do not actually remember it being specifically mentioned that the shop would install the same operating system. What I do remember though is that when my husband was on the phone to them before taking it into the shop, they asked whatoperating system we had and we just told then Windows XP Media Edition. I had no idea then that there was more than one version of it! It does clearly state 'Media Edition 2005' on the label on the top of the tower (the one shown in your picture) though.
One thing I am not clear about, but I am sure you will know the answer. When we first turn the computer on, we get the Dell logo screen. Is that just programmed in to come up automatically on a Dell computer, or does it mean that they used a Dell CD? I am just speculating here that guy in the shop who said he had owned a Dell
Dimension 9150 might have used his own disk.
The chkdsk thing is at 94 per cent now.