They still transfer. All you need is a wallet.dat Don't lose it. You'll lose your wallet if your "wallet.dat" gets deleted.
Is it a solution to copy wallet.dat than save it somewhere in the cloud? (like GDrive, or DropBox?) Thx!
Yes it is. But the wallet.dat should be encrypted! Anyone who has access to unencrypted wallet.dat (or is able to decrypt it) have access to your bitcoins in that wallet.
You can encrypt it in the bitcoin program or you can encrypt it independently (or both). Do not loose/forget the password!
What you can do is use TrueCrypt coupled with DropBox and encrypt it on bitcoin-qt.