Hi,
This is a problem we see from time to time with Windows XP.
On XP this happens because your operating system doesn't have enough window handles to server our program's request for handles. Handles are used to display GUI objects to the screen.
If you have multiple applications open at one time, can you shut some of the others down.
If you have many applications resident in your status bar, can you close all of them down, bar the essentials.
If you do not restart your machine regularly, can you do so, as handles can get lost as not all are always returned to the central operating system pool.
For Windows 7, this is far more likely to be a permissions issue during installation.
If you are running Windows 7, please right-click on the install file and select 'Run as Administrator'
This is a new Windows 7 security feature.

Please check that you do not have any security applications blocking the installation of XSitePro.
Also,
If installing XSitePro to the default location is not working:
Please reinstall XSitePro selecting c:\xsitepro for the program directory
and please select C:\xsitepro-data for the data directory.
_________________
Ben Fleeson
Empowering individuals to be financially independent.
http://xsiteprosupport.com/