The reason behind the electrum not launching is possibly there is a glitch that make the interface of the electrum not appear. It is also possible that there is conflict on the use of resources reason why the application just get listed on the task manager and yet the UI doesn't appear.
Find the wallet directory location: https://electrum.readthedocs.io/en/latest/faq.html#where-is-the-electrum-datadir-located
The data directory of Electrum is where wallet files, config settings, logs, blockchain headers, etc are stored.
On Windows:
Show hidden files
Go to \Users\YourUserName\AppData\Roaming\Electrum (or %APPDATA%\Electrum)
On Mac:
Open Finder
Go to folder (shift+cmd+G) and type ~/.electrum
On Linux:
Home Folder
Go -> Location and type ~/.electrum
Where is my wallet file located?
The default wallet file is called default_wallet, which is created when you first run the application and is located in the /wallets folder, inside the datadir.
Copy and paste your wallet file to your desktop or better your D disk as your backup. Even if you have the wallet seed backup, I still recommend you to copy and paste that wallet file.
Next, you uninstall Electrum wallet software, and reinstall it. If the new installed wallet software opens smoothly, you can copy and paste your wallet file to that directory location again, and use it. Or you can recover it from your wallet seed.