This problem is because you have not done all of the Windows updates. I thought in your Email to me that you could not reinstall the software. You can now reinstall the software, but I have this problem identified in the FAQ, so you must run all of the Windows Updates to fix this.
Here is the FAQ that you need to follow to fix it:
http://www.mtu.com/support/faq/faq-i...htm#SNMismatch
Also make sure that you have Hoster 3.120 that you are trying to Install. This was also updated in the Software to make this error not happen as much. You still must have all the Windows Updates though.