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but as i said it is a good idea to keep a backup just in case something went wrong. in your case make a copy of your wallet file and write down your private key(s) on a paper (eg. printing them in which case make sure your printer is not storing them in its memory).
your wallet file is here: %appdata%\Electrum\wallets
and your private key can be found either by right clicking on each address in your "Addresses" tab and selecting private key then entering your password. or you can go to "Wallet > Private keys > export" from the menu and export all your keys.
Thanks. I want to ask one more question, how to make a backup?
Did you even read the post you have quoted ?
It is pretty hard to explain it even more detailed. I guess you can figure out yourself how to copy a file on windows.. If not, take a look
here.
Note, that your wallet format is deprecated. It is recommended to use (modern) HD-wallets.
This will save you a lot of time in case of something going wrong at any time in the future.