Re: So you did not back up the OEM installation files then
I did mine back in the day (x520)
Still have most of them somewhere, probably on rotted-to-hell DVD-R and pressed disks but may be readable.
Did anyone get anywhere with the "recovery" method of selectively zapping damaged DVDs with a finely focused blue or green single mode laser diode to get them to read again?
Most of the forensics tools I use won't even see past the TOC, data *was* there at one point but alas not recoverable.