CAN'T REINSTALL ITUNES/QUICKTIME, please help

Hello,


ok. so about a week ago, I bought about ten apps for my ipod touch. this was the first time i had done this. Itunes told me that i not only needed to upgrade to itunes 9.2, but I also needed to upgrade to iOS 4 in order for my apps to work on my ipod. I tried to upgrade using both the itunes site and the apple site but it keeps telling me that Quicktime wont install because my computer can't access "network location %APPDATA%/. I have tried deauthorizing my itunes and quicktime and all things apple related because that is what the guy at Best Buy told me to do, but now I can't even access itunes at all and my ipod only shows me the screen asking me to connect to itunes. I am so stuck and I really really miss my ipod. can someone please help me out? Thanks.