Your homepage seems to be have been "Hijacked" by the website you mention!
Any change you make will be reversed by this "hijack" therefore making any change you make useless.
Microsoft have a big article on this and does include editing the registry. You can find it if you click this >
http://support.microsoft.com/?kbid=320159
Howev
er,
there is a free piece of software that will revert and keep the change you make to the homepage setting. This will also stop the homepage from changing in the future. The software is called "Startpage guard" and can be found here >
http://www.spywareinfo.com/downloads/spg/
There
maybe more to it then this so i would suggest you download "Adaware 6.0" from here >
http://lavasoft.element5.com/support/download/
Install, UPDATE and then scan your PC. It will scan and (may) find such nasties as a "hijack". Adaware 6 is an easy program to use. However there is a more powerful program (as it has extra features) that will also scan your PC for nasties. It is known as Spybot S & D and will find things that adaware will not (and visa versa). If you do download this use caution as it can identify files and registry entries that you may need. You can find it if you click here >
http://beam.to/spybotsd
As
for editing the registry Microsoft have a very detailed explanation on this... >
http://support.microsoft.com/?kbid=256986