BSOD Windows Memory Diagnostic Tool stops at 88% complete

Well after 4 weeks Acer have repaired my computer. The report states that they had to replace the mother board and reinstall the OS. Their final test states that the system recovered!
Unfortunately, that "recovery" meant that they reinstalled the original software which was just FreeDOS and totally useless! At least the commands worked this time.
Sadly they managed to leave some old data so that when I went to install Win 7 all over again, the install from DVD thought that I needed to repair and not install. So the opening menu did not include an Install option!
I think that the quickest way out of that is just to use Partition Wizard to wipe the HDD and format as NTFS ready to start the Win7 DVD from scratch.
It has been a very long and painful process so far and installing from scratch means even more hours getting hundreds of updates once the OS is in place. Luckily I never installed anything much in the way of programmes.
Tony

My memtest result indicated to me that either the card or the socket/interface was faulty. Eventually Acer accepted the screenshots as confirmation and agreed to make a repair at no expense to me.

They found that the card was OK but the motherboard was not! So replaced it completely.

I got the PC back yesterday and ran memtest. No problems reported. So now I have to install an OS all over again.

As the PC is now surplus to requirements (we bought my wife a Lenovo with 8.1 preinstalled - cheaper and worked straight off!) I will use the Acer PC to run the Win 10 preview and see how that works.

Thanks for all the good advice. I have learnt a lot that I never expected to need to

Tony