I've been in a net with 20 informatic experts playing a online game.
Are there risks they could have access to my pc while connected on the radmin net?
I have an unupdated windows 7.
I've done a lot of attempts unistalling radmin vpn but I always got this error that denied me to complete the unistallation: "A problem has occurred with this Windows Installer package. A program executed during the installation terminated unexpectedly. Contact support staff or the package vendor".
Yesterday finally the unistallation process completed succesfully I don't know why.

If you set up firewall and antivirus and use a strong password in Radmin VPN network, its not risky. Moreover, you can turn off Radmin VPN by clicking the round button and no one will be able to connect you.
IF you have an installation problem, try this:
https://support.microsoft.com/en-gb/help/17588/windows-fix-problems-that-block-programs-being-instal...