I used to goto cartoon websites and play unallowed computer games, nothing inappropriate, just spongbob stuff, which got me permanently banned from watching spongbob at home.

The school would keep using Internet Explore 6, I'd update it to iE 8. They didn't like that.

I'd also would install some toolbars, there was this one yahoo one, that added tabbed browsing to iE6. :)

Updating to iE8 on only one older computer caused problems, but the newer machines worked fine with iE8. ;)

I would install Firefox, Opera, Google Chrome and Apple's Safari for Windows web browsers. I enjoyed testing and find the best browsers back then.... Staff weren't to happy though.

I'd change desktop wallpaper to windows XP's Bliss, instead of the schools preset solid colour background.

As i got older, I learned how to write batch and vbs scripts to automate different things, so i wrote a tool to automatically login to some of my required school accounts, without me needing to manually type in my login credentials each time. Staff either didn't know or didn't mind this.