remove all logins how?

[Ich?]

how can i delete all logins if somebody ´have acces to my acc from a other pc

[RemyXIII®]

https://store.steampowered.com/twofactor/manage

click on deauthorize all other devices

[Wolf Knight]

this will make sure they are completely removed from the account

1. Scan for malware https://www.malwarebytes.com/
2. Deauthorize all other devices https://store.steampowered.com/twofactor/manage
3. Change passwords from a clean computer
4. Generate new backup codes for your Mobile App https://store.steampowered.com/twofactor/manage
5. Revoke the API key https://steamcommunity.com/dev/apikey (there should be nothing in the APIKEY)