Your original Tiger installation disk should –*in a worst case scenario –*solve this by reinstalling Tiger. But I guess depending on what exactly you did, there should be an easier way. So yeah: What _did_ you do?
erm i downloaded 3 icon sets and usin some software changed the icons. i then used a different software which had a reset feature which i have tried. This only reverts them back to the ones i had used with the first software