And I'm even more puzzled about what to do about the Trojan Horse. Any suggestions???
Well a Trojan horse or just Trojan is the context of computing and software, a Trojan horse, or simply trojan, is a piece of software which appears to perform a certain action but in fact performs another such as a computer virus. Contrary to popular belief, this action, usually encoded in a hidden payload, may or may not be actually malicious, but Trojan horses are notorious today for their use in the installation of backdoor programs. Simply put, a Trojan horse is not a computer virus. Unlike such malware, it does not propagate by self-replication but relies heavily on the exploitation of an end-user (see Social engineering). It is instead a categorical attribute which can encompass many different forms of codes. Therefore, a computer worm or virus may be a Trojan horse. The term is derived from the classical story of the Trojan Horse.
In the field of computer architecture, 'Trojan Horse' can also refer to security loopholes that allow kernel code to access anything for which it is not authorized.
I noticed that the reference you gave has an entension of ".url". I've begun to notice that some downloads also have this extension. Just what is it and what does it do?
I'm not sure what you mean by ".url" extension? The link I posted was http://www.samsunsegman.com/um/
so where is the url?
Uninstall Manager scans your hard drive for a list of its contents, file wise. The next time you run it, it will tell you what extra files have been added and tell you the file, location, date and time. So have to decide if you want to keep these files or send them to the Recycle bin. You can set it to forget certain folders that are constantly been updated e.g. Temporary Internet Files, Cookies, Recent Documents etc
This way you will notice what as been installed without your knowledge while you have been surfing. You can also do a System Restore. As I said its a bit late in your case because you don't know what as been installed without your knowledge.
Just do a full virus check and see what it picks up.