Beware, if you use Electrum on a computer with malware you can easily lose your funds.
The easier approach is to save separately (in a text file) the address/addresses you know you have funds in and check them on a block explorer (since it's only addresses that's public info and no harm can be done).
Also beware, the 2017 Electrum have big issues and may trick you into downloading a malicious Electrum-like looking software. I advise you download the latest version (
https://electrum.org/#download) and verify it (
https://bitcoinelectrum.com/how-to-verify-your-electrum-download/).
Thanks for the advice, although an infected computer is generally not a good basis of doing anything finance related.
The more I read about wallets the more I read about hardware ledgers which seem to deliver superior safety. I had another idea of just using a old Laptop with a fresh Linux Mint system to manage the wallets and transactions and nothing more. Risks of malware/trojans would be close to 0, not only because of Linux, but because of no other usage.