wallet.dat on usb to electrum I put my btc qt wallet.dat file on a USB and would like to open it on a software wallet. Preferably electrum. Is that possible?

If so how?

Too many problems with btc qt and takes forever to sync.
Electrum does not support bitcoin core wallet files. What you can do is dump all the private keys using bitcoin core and then import them into electrum. So first make sure that the wallet.dat file is in bitcoin core's data directory and then launch bitcoin qt, go to window menu > console and unlock your wallet:

walletpassphrase your-wallet-passphrase 300


Then dump the wallet to a file on your filesystem:

dumpwallet C:\path\to\new\file


Open that file using a plain text editor like notepad and you'll see your private keys in the row to the left. for example:

# Wallet dump created by Bitcoin v0.18.0
# * Created on 2020-01-16T09:48:08Z
# * Best block at time of backup was 115144 (0000000000000c76185d6ab9b04672082d8d9a876fbe9f908c63bd9ec5d02433),
#   mined on 2011-03-26T14:26:44Z

# extended private masterkey: xprv9s21ZrQH143K4UvtqjsWXxXBSDkxVbwePkX2ofaCRhrB2xBcMaFxnWBvZBKnTmgdc32cKc6PbmGCd1LB6X8K9JUGqqVGvxoWbEh231FB6x6

KyDFvw3oUNsJ1rFgAX4VQ5ffP5kpkeStU9kjyA3vAm5EpjF21TMh 2019-01-16T15:33:42Z change=1 # addr=3QKaCD7kQrwstfMvEYbv3iDuXPFLUUoj4p hdkeypath=m/0'/0'/874'
L3tWcLep3Vmhoq3eQFQioycDdyFvpdLBfmvBYHdSBH3bBepE5KR9 2019-01-16T15:33:42Z change=1 # addr=32ubG76VZ23TUWYf8ZGaU7MwFs1bJVbd3r hdkeypath=m/0'/0'/395'
KwQH7xszobX5ByvsTdFrhVrCshyZG3aLa1cagcv5rJghGHuQStuK 2019-01-16T15:33:42Z change=1 # addr=3GfzM8BRgQj6FtGvZZUfLKaE9KTfL39A1B hdkeypath=m/0'/0'/499'
L5Q4SnnKvvSoCDaz2GvQkWWLgjJx5aMXogRvjJHfQG9faXLmaNLM 2019-01-16T15:33:42Z change=1 # addr=3GWHaeXKBoAxa23MHRknaygDosJiWTiMP1 hdkeypath=m/0'/1'/159'
L3Bnvj1xTJFMzXsym7jBDMLbz5qhxotq8La4UxDdhKZnmZ4s1nw1 2019-01-16T15:33:42Z change=1 # addr=39WoYcrRnY9vRBuxSCmU4vtdEvnWRcn5QJ hdkeypath=m/0'/1'/918'


Your private keys are the strings that begin with K, L or 5 and are in the left most column.

Now to import them in electrum you download and install electrum and run it. The first time you run it it'll let you create a new wallet file. If this is not the first time you are running it use file > new/restore to create a new wallet file or simply enter a unique file name in the first window that pops up when you run electrum. During the wallet creation process choose "import bitcoin addresses or private keys" in the first step and in the next step enter the private keys one per line with either "p2wpkh:" for bc1 addresses or "p2wpkh-p2sh:" for addresses that begin with 3 prepended to each private key. If your address begins with 1 you don't have to enter a prefix. For example:

KyDFvw3oUNsJ1rFgAX4VQ5ffP5kpkeStU9kjyA3vAm5EpjF21TMh


becomes

p2wpkh-p2sh:KyDFvw3oUNsJ1rFgAX4VQ5ffP5kpkeStU9kjyA3vAm5EpjF21TMh


Follow on-screen instructions for the rest. Note that if you know exactly which addresses have coins sent to them you can import just those addresses' private keys.