also, you can download "process explorer" procexp.exe from sysinternals.com
www.sysinternals.com/ntw2k/freeware/procexp.shtml
It's like Windows Task Manager on steroids, in that you can kill *any* process. Use the "Find Handle" to locate which executable currently has the .dll open. Kill that process tree, then with Windows explorer go find the .dll on your hard drive and delete it.
I've used this on other spyware/crap that was holding files open.
Also, useful to educate yourself on what is getting launched at boot time. Be Very Careful so you don't screw something up.
Click Start, Run, type in "regedit", and do a search for "runonce" You are really looking for the key "Run" which will be right above "RunOnce" but the word "run", all by itself shows up a bazillion times in the system registry. Speeds up the search.
Look in the Run, RunServices, RunOnce, RunServicesOnce for suspicious entries.
What I do, instead of just deleting an entry is disable it by modifying the command line.
Example, spybot launches using "C:\Program Files\Spybot - Search & Destroy\TeaTimer.exe"
I can disable it by modifying the string to read "_C:\Program Files\Spybot - Search & Destroy\TeaTimer.exe"
viola! regedit can't launch it, but it is very easily reversible if I disable something I need and I want to put it back.
Also, look in the "Startup" folder in "Programs" for what's getting launched there.
I also run two different spyware hunters, Spybot and Ad-Aware. They have different search engines and give slightly different results.