Cannot restart Vista

I just had a disaster that apparently many people have experienced and there
should be a solution. I was trying to delete some very unnecessary files
from my external hard drive that not amenable to a regular procedure with
deleting thru Windows Explorer==>Left Click==>Delete even with elevation of
all sorts and giving myself full control of that folder. I need to reformat
that folder eventually.

The only thing that worked was running a command prompt as administrator and
deleting files via DOS commands folder by folder. I got tired of it and
decided that I should turn the UAC temporarily and see if this could help me
to delete the directory wholesale. The computer said that it need a restart,
turned off and when an attempt to restart came up if won't start Windows.

I am typing this method in safe mode. What is the solution?

I do have an image of the system, or rather my C: boot disk saved about 3
hours ago but after that I did some work. I can sacrifice it for sure but I
am wondering if there is something simple that can be done in cases like
this?

Thanks.