Recovering old Sony laptop

Hi I have a Sony PCG-F808K old but no problems (until now)Having collected crap files, corrupt bits and general detritus over the years. It was time recover the computer before handing it over to my daughter for college.

First part all goes well whilst hard disk was cleared. Then having reset the partitions to the ex-factory default and started to reload applications. All proceeds OK until 20% then it stops and says 120% completed
Critical error: Abort, Retry, Ignore, Fail? Nothing happens when I click on these.

I have had no joy from support. Any Ideas ? The only modification to the computer from new was extra memory fitted. Worked fine after this until now.