sync iphone4 with new itunes ... ?

hi ..

i have iphone4 unfortunatley i had to install a new windows so i installed a new itunes
so that i can't sync my iphone 4 or copy any music from my library and i can't erase everything on my iphone
i tried many things the last one was the manual mode but it failled because it wants to erase everything on the iphone4

thank you for reading problem

i hope you can help me 🙂🙂🙂🙂