General discussion

My university mandates GP VPN to connect to its computers. I was using version 5.2 , suddenly from today it is auto updating to version 6.1 which doesn't seem to work with my Win 8.1 . I tried to reinstall old versions like 5.1 or 5.2 , but within minutes after installation it is auto-updating to latest version which doesn't work. I simply have no control to stop this auto-update and which never happened before. Any remedies ? Thanks