How to fix Class not registered or 80040154 error

Last update: 25 Jun 2005 | 200889 views

"Class not registered" is one of the most annoying and frustrating error message I ever got because none of the video files can be played by Windows Media Player, Media Player Classic or other DirectShow player and common fix methods (Windows Media Player reinstallation/upgrade, codec reinstallation...) seems to fail.
Fortunately, the solution (in fact one of them because there are few different solutions) for this problem is very simple.

After some research I found that quartz.dll (a DirectX related DLL) wasn't registered correctly.

How to register it? Click on Start > Run... > and type regsvr32 quartz.dll

Run dialog box

In the end, you should receive a message saying that your file was succesfully installed.

The file was succesfully installed

Note: Please, let us know if the solution suggested here wasn't helpful for you so we can try to complete this guide with other hints.

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Tryed it 5 times but message still the same with "Absolute Sound recorder" and can not even quit the program besides the Ctr+Alt+Del???? Message keeps popping up?

Rating: 5 | on 10 Aug 2012, written by: Kees van Haaren

I got the successful message but I still have the problem.

Rating: 3 | on 26 Jun 2012, written by: Ted Taylor

Man, thank ya! DirectShow and any codec was working correctly! This works as a charm, thank!

Rating: 5 | on 14 May 2012, written by: Robson

i am new at playing pc games but I don't even know where run is at. when i click on start run does not come up. what am i doing wrong??????

Rating: 1 | on 09 May 2012, written by: Debbie

This does not work.

Rating: 2 | on 06 May 2012, written by: julie

So easy. I've spent a couple of weeks trying to figure this problem out and you solved it in seconds. Thank you!

Rating: 5 | on 04 May 2012, written by: MarcP

Thanks! Spent many hours trying to fix this until I finally ran across this tip!

Rating: 5 | on 02 Mar 2012, written by: scschl

Wow, worked like a charm in seconds...after hours of research and trying other suggestions to fix this problem, THANK YOU!!!

Rating: 5 | on 30 Jan 2012, written by: Angie

I came across this when I was trying to find a solution to my problem. It looks like some of the people responding are merging regsvr32 and quartz.dll and mispelling regsvr32. There is a space between regsvr32 and quartz.dll. Regsvr32 is an exe that registers dll's. Hope this helps might not help the people that posted because they might have found other help but maybe the next individual that reads. If not, I tried :)

Rating: 3 | on 13 Jan 2012, written by: Daisy

It did gave me quartz.dll succeeded but still am facing the same problem. What next???

Rating: 2 | on 09 Jan 2012, written by: Ahmed Khan

Did not help. I just downloaded newest version of Movie Maker and updates, latest Direct X, ran registry tools, etc. Everything else is just fine, but cannot download from Sony HandyCam MiniDV without this error. Thanks for trying.

Rating: 2 | on 05 Dec 2011, written by: Henry J Powsner

Not much of a Windows is stuff like this, unexplained errors, that drives me nuts. Even less of a MAC fan, though. Thank you for your help. I can hear my airhorn sfx now.

Rating: 5 | on 20 Nov 2011, written by: Beeber


Rating: 2 | on 24 Oct 2011, written by: Nick

Not worked cannot find regsv32quartz.dll ,,, loads of solutions out there,,, no answers

Rating: 5 | on 11 Oct 2011, written by: Chris

did not work message saying "cannot find regsv32quartz.dll"

Rating: 5 | on 25 Sep 2011, written by: davie mccartney


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