Have you tried running system restore in "Safe Mode" yet?
If not, please try doing just that by pressing the F8 key while
the computer is booting. You should then get a menu that will
allow you to start the computer in "Safe Mode" and once it is
booted, you can then try running system restore again.
The above will allow you to run system restore without most of
the programs that usually get started when you boot the computer,
getting in the way of the system restore.