am a happy chappy as i saw a sealed 5th ann oblivion at my local supermarket pc for ￡7.00

the downside is that my pc is slightly underpowered for oblivion (1.8 ghz pentium 4).

i have used oldblivion before to play oblivion and i can get the main game to run,BUT i cannot get either kotn or si to work?

have googled oldblivion but my pc only brings up a pic of tumbleweed (bad joke,it doesn't go to the oldblivion forum).

any help would be most welcome (do not have a console to play it/no funds to upgrade my ancient pc).

thank you kindly