internet slow after using Air VPN

[chancee4 0]

I've been having a strange problem for the last few weeks.. The internet in my entire house has become brutally slow, on all computers - the whole network.  A tech from my internet service provider has been out to my house twice and verified that my signal is fine in the house... the problem is my computers/network.  I hadn't used Air VPN in about a month and a few days ago when I connected... as soon as I signed off, this problem began.  Same thing happened a few months ago... and eventually is started working again.

 

I'm wondering if using the VPN has somehow changed one of my internet/network settings?  I've also gotten a strange error message a couple of times in the last few days telling me another computer in the house is using the same IP address and there is a conflict...?  Could this have something with using the VPN?  Any help will be appreciated.  Thanks, Chance