What's the Best and Easiest Way to Remotely Connect to Network

I know next to nothing about remote connections beyond the fact that my ISP always seems to want to do it for the most trivial problems.

I have a friend who has a company called Right Network hosting their QuickBooks. They can use any of their various home PCs to access QBs. However my friend also has a laptop that he takes out on the road and he wants to have that same access when he's away from home.

I don't know what the best method is for that. Windows 7 has a thing called Remote Assistance, as well as Remote Desktop. But when I use his laptop and go into Control Panel/System/Remote Settings, I see that although there is a check mark in the box Allow Remote Assistance connections to the computer, the lower half of that screen which pertains to Remote Desktop is grayed out. So I don't know what's up with that.

And I don't know what tools to use. LogMeIn? TeamViewer? Should we be looking into VPN?

They pretty much have their computers on all the time, but there might not be someone there to enter any sort of code as happens when my ISP remotely connects.

Thank you very much. I'll give it a try.

I also use teamviewer, but for personal use, you may consider UltraVNC, or some other free VNC application.