This dll is problably missing from your files or is either corrupted...
just download it and paste to the correct windows folder, (it must have gotten corrupted as consequence from your crash).
check this link to download the dll:
mscorlib.dll download - free dll files
the only problem will be finding the corrupted dll, since its quite present all over your windows (check this prntscrn)
I can't help you finding it, but you can give it a try