I've inherited a network where PPTP is used as a VPN method for remote users. Obviously this is a security concern. I'm looking around to improve this but I'm not sure which way to go. I was thinking about SSTP or just a third party solution. Probably a third party solution would be the best but I'm looking for a free or very cheap solution. I'm running Windows 2012 R2 and most users have Windows 7/8.