Questionable files

How do you know or can find out for certain if certain files are necessary or a hindrance to your computer? I ran Sophos Anti-Rootkit and it found several files that I find questionable even though the recommendation from the program were not to remove them.

For example, there is a UIRibbon.dll file under the ~winsxs/amd64_microsoft-windows file that I think I should be able to remove, as I'm using Intel Core i5 CPU chip set, but the program is recommending not to remove this file. What is the snapshot.elt file used for?

Also, is there a website that I can trust to find out what other files are used for and if it is possible to remove them?

 

Greetings, roboman123.

UIRibbon.dll is a Windows component: http://www.win7dll.info/uiribbon_dll.html. Don't know if it's needed, as such, but IMO I sure wouldn't remove it, especially if it's not causing any problems.

As far as finding out about files, it's pretty much up to you as to how deep you're willing to dig. I use FILExt.com for researching extensions, and VirusTotal for suspicious files.