How do I verify if a file is actually infected?

A while back NOD32 (v. 4.0.424.0) quarantined BthHelpcdrom.dll. Now, every time I boot up I get an error message that this file can't be found. Other than that, its lack appears to have no effect on my system.

How do I verify that this file is, indeed, infected with something. If it isn't, I'd like to get it out of quarantine and restore it so as to eliminate the error message.

Failing that (or if it is infected), I'd like to get a replacement for it. I googled it, but could find nothing on this particular .dll file.

Thanks for any help.

 

let eset check it
http://kb.eset.com/esetkb/index?page=content&id=SOLN141

 

Upload it to VirusTotal and Comodo Instant Malware Analysis (or ThreatExpert).

More options here: http://www.techsupportalert.com/content/how-tell-if-file-malicious.htm

 

How do I get access to zip it up and send it to ESET in accordance with the instructions at the above link? I can look at it in the NOD32 quarantine screen under tools, but the only option I have is to restore or delete it.

When I search for the file in my system, I get nothing....even searching hidden folders. It looks like things in quarantine are renamed or something. I have no idea where the quarantine folders are located on my system.

Do I restore it, then zip a copy and send it? This seems a mite dangerous.

Thanks for any help