Q: cant download itunes on sony vaio windows 8

I need help please

I purchased a sony vaio a few weeks ago with windows 8 now i cant seem to get my itunes to either download or to work

I initially installed itunes before i activated my norton internet security and i was able to get itunes to download and play music no bother but then when i plugged my iPhone 5 in to sync to the new computer it ended up having a few problems

1. it either said that it couldnt sync due to an error code 0xE8004002

2. it said it couldnt read my iphone and to restore to factory settings

on the first problem i just ejected the iphone and did a reboot and i reboot the computer also but then when i connected again i then got the second error

so i backed everything up on icloud that i could and then  tried to restore to factory settings but then another error came up saying that due to an unknown error i could not restore the iphone

i looked at forums and i saw that i should just manually restore from the iphone itself which i did but then icloud lost have my notes that i had but itunes recognised the phone and sync did start but then half way through said that songs could not be snyc'd due to an error and then all my music was greyed out and i couldnt play it

Then i had to begin again with all the errors of not connecting

i then read more forums and was advised to delete itunes then reinstall again.  I uninstalled but now i cant get it to reinstall again.  Internet explorer keeps saying download interupted when i get to 99% and it will not go any further and google chrome says pc doesnt allow download check internet settings

please help because im about going barmy with this

thanks