reinstall os only

HI Eric Root

I've looked into my backup and my programs are there DUH!!! but the reason to reinstall is that when i try to install an update from the apple store it will stop and i get the grey screen and restart with the screen sent a report to apple, i,ve done a hardware test and all ok.

Now i have update my apple id account to one with an @.com and i'm locked out so a phone call to apple care to sort that one out, thanks for the help will let you know how it works out.

Well all is well on the western front, I rung apple care and it turn out the some startup progs had to be removed and some from the libray, out come all works fine now, but many thanks for your input, I will have to make time every couple of weeks to do maintaince, but it work so well I forget, (unlike you know how???)