IPhone 4s takes forever to backup?

Here's by problem:
I'm trying to use my brother's iPhone for a while and I want to back it up.
When I try to do so, it takes forever for iTunes to backup.
I just want to backup contacts, SMS and Camera Roll, I backed up contacts into my email using an app, copied all camera roll pictures to my PC and deleted it on the iPhone. I removed all apps, musics, videos. Now the phone only contains some messages and there's no way to back them up and even then the backup gets stuck.

Further problem: somewhere on the apple forum someone recommended using command "netsh winsock reset" in command prompt… I used it, restarted my PC and iTunes no longer finds my iPhone even though it is successfully connected to my PC

More details:
iPhone 4S, iOS7, Windows 7 Desktop.

Added (1). I have deleted all games, apps, musics, videos… This is some error.

No not really. It depends on how many storage he has. He probably has to many games or photos and stuff like that

Use iCloud, Simple & easy

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