Hi, just wanted to tell you that i reran The MS Fix it tool, but this time on the agressive setting. And i have been finally able to install some updates. I am right now installing the missing ones. Not sure yet if they're all going to work...
Anyway, I wanted to thank you guys because you have been really helpful
EDIT: IE9 won't install...It says it can't finish the install. I already tried the troubleshooting steps proposed by microsoft, and tried in clean boot mode. With no sucess so far...
Windows 7 x64 SP1 fails to install with error code 80073701

DOUBLEDIT: Never mind, problem finally solved:
http://marcin.malkowski.eu/2011/03/02/ 
Thanks for your help guys