Manually manage music on new computer with old iPhone 4

[LeiQQ]

Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)

I'm posting here in hopes of getting some help for a friend. My friend's windows laptop has died. He was manually managing music for his iphone 4 that he kept stored on an external hd. Now he wants to use his iPhone 4 with a Mac mini without having the music he added to his phone before deleted. He's still using iOS 4.x. He doesn't want to auto sync. Is he going to have any trouble when he hooks up to the mini? Is he going to need to add his music to his iPhone again?

 

[Dave Braine]

Is he going to need to add his music to his iPhone again?

When syncing to the new computer, he will have to choose what he wants synced. If he wants the music that's on his iPhone to stay there, choosing not to sync music should do the trick.

However, if he subsequently wants to sync music that is on the Mac, it will delete what's already on the iPhone.

 

[LeiQQ]

When syncing to the new computer, he will have to choose what he wants synced. If he wants the music that's on his iPhone to stay there, choosing not to sync music should do the trick.

However, if he subsequently wants to sync music that is on the Mac, it will delete what's already on the iPhone.

I had a look at his new computer and downloaded his apps based on his apple id but I'm wondering if he updates to iso5 will he lose all his app data? The old computer is dead so I don't think he can get anything off it. If he updates to iso5 he's going to lose everything, right?