if your computer run faster in safe mode than the normal mode maybe you have a big probleme with your systeme, befor making anything on a unstable systeme, maybe its a good idea to fix it befor making anything.
try to download hijackthis run it and disable all the think you don't know or you don't want to run at the statup.
personnally i don't think any programe as to run at startup, why on earth the programmer put programme in the run forlder or make it run at startup ( ok i talk about personnal computer not compagnie )
First if anything can fix it, format your pc and reinstalle windows on it maybe it will be better becose you mat have a lots of infection in your pc ( spyware and virus ) that may cause your pc run like very slower than usual.
Safe mode are only used to fix some probleme with the c and not run something. If you want to run a programme in safe mode, you have to go in the services msc thing and load everything you want everytime, "video card driver ( if you load the video card, you have to reboot and if you reboot again in safe mode, the videocard will be disable again ), Dirext X dll ( same as the video card), all the sound setting if you have a good sound card, etc..
good luck
If you can, I can!