ummmmm.... you are doing it wrong!!!
Here's the deal... If you follow Mr. Do's instructions you will be fine.
Make sure you get all of the patches. That would be:
http://mamedev.org/updates.html 0145u1.diff
0145u2.diff
0145u3.diff
0145u4.diff
0145u5.diff
then
hi_145u1.diff
If you made the name change when you were saving the file and ended up with .diff.txt, rename the file without the .txt extension. What you did was NOT change the file type setting at the bottom of the save window. So you changed the name only, and the file type stayed .txt.
patchmame in that order!!! If you don't it will never work. If the source is patched out of order the lines will not match and everything goes to shite.
so.. assuming you did everything correct so far it would be:
patchmame 0145u1 <enter>
patchmame 0145u2 <enter>
and so on until you have applied them all, including the hi_145 diff
Then makemame...
The key here is to go back and start over. Read the directions very carefully, and do them in order stated. If at any point you get a result different than what you are supposed to, you have made an error. Blowing up your windows install isn't part of the equation, and I have no hope of guessing how the fark you managed that lol!