In order to install Activehome Pro, the software would actually look to X10's servers for the current version and to activate the copy.  Unfortunately X10 went out of business earlier in 2013 and as a result their servers were shut down and it is not possible to register or install the software any longer. 

We have been moving away from X10 technology since around 2010 and stopped selling Activehome Pro in 2011 so there is no longer any warranty on this product and we are not aware of any way to re-install or activate a copy.

If you visit x10.com it will redirect to a company who appears to be trying to maintain the brand and even manufacture some product.  They may be able to lend some warranty support but the only known option is a plug-in mini timer.

We recommend that you consider the Insteon Hub.  This a network based automation hub offering email and SMS alerts, remote control, and scheduling.  It is primarily for Insteon but also supports X10 devices so it might be a good way to get up and running with your existing X10 set up while offering a migration path to Insteon which is a much newer, more secure, more reliable technology.

X10 was around as a technology for over 35 years and the sun is setting.