ok, go to
http://www.microsoft.com to download the latest ver. of Direct X
and go to your Video card's website and download the latest ver. driver (i know what video card you are using, so i can't give u the website for that)
then, install your latest ver. of Direct X you've just downloaded. now this one is done.
then go to control panel, add or remove programme, select your video card driver and click remove, go through all those "are you sure you want to remove the selected....blah blah blah "
restart your computer....then install the new video card drivers u just downloaded. go through those blah blah blah.....all done and run SRO, see if it works....
since you saying you don't know anything about computer, i assume you didn't touch any setting of overclocking your cpu, so just leave it as it is.
as for formatting your computer, is a bit hard to tell you how to do it when u know nothing about computers, so, if after all those steps above and your computer still restarts when playing SRO, get someone who knows about computer to help u to do the formatting.
hope this helps ya