use www.logmein.com . The simplest and the best for free.
It supports ActiveX based Remote Access on Internet Explorer, of if you are using some other browser, then it also supports Java Applets.

Or if you cannot use either ActiveX or Java applets, then it also has a software called LogMeIn Ignite, which is a portable application for remote access i.e You can carry it anywhere with you, and access your home PC without having to install anything on the computer you want to access from.

Definitely give it a try first.