Maybe you need Admin rights to use it i dont know, do you have admin rights when you log on normal?
There is 2 good tweakprograms
1. cablenut, most advanced tweakprogram i ever seen, no spyware, wont mess up your registry, if you dont like the tweaks just click delete cablenut tweaks and save to registry, then you have all parameters to windows defult.
2, TCP Optimizer (less good if you ask me) It helps alot of ppl, works best for fast connections above 3 Mbps downloadspeed, somone was saying it has spyware, im not so sure about that never seen it myself. The problem with this program is that it dosent care how big your bandwidth is it just set same values for all connection types. It also dosent autoclean when uninstalling, you need a backup from your registry to fully restore your PC if your not happy with result.
and do not use both program at same time, that can mess up your TCP settings alot.
VanBuren