i think it works now. It is showing status "Importing blocks from disk". But still importing overnight, still takes time. Thank you all for your kind support
It should be noticeably faster because it's not downloading the blocks from other nodes but importing them from the disk. However, it still has to verify the blockchain data, so that does take time. Also, the bootstrap.dat file will only cover up until block height 317000, and then it will have to start downloading blocks again.