Bitcoin wallet shows empty after I installed Windows on SSD My PC stopped working a while ago (BSoD on every restart). I bought an SSD and installed Windows 7 64-bit on it (same as I had on my HDD). I then attached the HDD back into my PC and intended to back up everything important before I formatted it. All my old files are still on the HDD, including Bitcoin-Qt and my wallet.dat. Which is why my coins should also be there, right?

I now opened my wallet, but I noticed it shows my balance is 0.00 BTC. It hasn't yet synchronized fully with the web (about 23,000 blocks left as I'm writing this), and shows it's not up to date. It also shows none of my transactions or anything.

Previously (before buying the SSD) the wallet still showed my BTCs despite it not being fully synchronized.

I have tried to run Bitcoin-Qt with the -rescan command, but this didn't help. 

Is there anything I can do to see if my coins still are there and to get them back? I'm afraid that if I let it synchronize fully then all this becomes somehow permanent..
Depending on how recently you purchased/mined your bitcoins, the fact that your client hasn't synced might be why you don't see any balance being shown. 

The reason for this is that your wallet doesn't actually contain any physical data representing coins, it simply contains keys that allow you to spend the values associated with a specific address. The way that the bitcoin network determines the number of coins associated with an address is by traversing the entire blockchain and summing all of the transactions including that address. When the bitcoin qt client is syncing, it is downloading this blockchain. Therefore, if all of your transactions happened in the blocks that you have not downloaded yet, it will look like your wallet contains no coins.

This means that the solution to your problem may be to just wait until the bitcoin client has fully synced. If/when your client downloads the blocks with your transactions in them, your balance will be updated. If your client syncs and you do not see your balance change, that means that the bitcoin client is not reading the correct wallet. Make sure that you have copied the wallet.dat file from your old hard drive to the correct place on your new one. NOTE: Make sure that the bitcoin client is CLOSED when you copy the wallet.dat file.

If your client has fully synced and you are sure that the correct wallet.dat file is loaded, and you still do not see your balance updated then you are probably out of luck. If you have lost the cryptographic keys stored in your wallet.dat file, the damage has already been permanently done.