I uninstall PPTP by mistake, and can't connect to internet anymore by my VPN. as i have only vpn connection to connect internet so i can't do it by software center or using apt get-install. so i download Debian package and put it in my local file system. but while trying to install i got warning that it's not a trusted source. then i have click OK which kill the instillation procedure or click Repair which check cache query and doesn't give any improvement. Now what should i do?
i don't want re-install again Ubuntu. is there any way to go back my good system?
plz help me.