I did select the first/last 2kb option, because I was looking for something quicker. Like I said, I can't restore or reformat because I don't have those privileges.
When the errors first started happening I tried some first aid, replacing files that did not work one at a time. I had boot problems at first, with multiple DOS windows showing that files were trying to load or run or were supposed to but were hanging up. I copied files from other computers and replaced the non-functioning ones on my computer, and I had some luck with that. Until I got to the ntvdm.exe file, which seems to run a lot of programs. I have not been able to replace it because it always seems to be in use. I don't have access to any safe modes. I believe that the corrupt ntvdm.exe is at the root of all of my problems & that replacing it will solve most.
I have run registry correctors but there is no change. Is there a trick or a process for replacing the ntvdm.exe file? I am reluctant to call any tech people because they will probably have a problem with me installing eraser on my pc.
I appreciate everyone's time.