I've tried doing run and "regsvr32 quartz.dll" to sovle an error message 0x80040154 but I once again got D11RegisterServer in quartz failed return code 0x80040154

I'm also wondering if this has something to do with the fact I have been getting an Audio Tag 8192 error message when trying to play a movie and hence getting no sound??

Help appreciated!

eeye advisory on Quartz heap corruption exploit (worth reading in any case.)

MS05-050 Security Bulletin related info
Are all your security patches installed? You may want to try to fix a problem with this dll by installing or reinstalling the appropriate MS security patch. That should take care of getting the quartz.dll registered and also make sure that security is current.

You'll want to register the correct version of the dll - a search for the file will likely show that you have more than one on your machine. The MS link above may help you to determine that.

Error Message: 0x80040154 : Class Not Registered (MS article ID 277964) describes the manual registration of system components.
The manual registration using regsvr32 requires correct path information - as in regsvr32 "%root%\[path]\quartz.dll". So.. you will need to specify the appropriate path to the quartz.dll file you are attempting to register. Although I have not verified this and it is not mentioned in the MS article, it appears that when regsvr32 is run from a location other than that where the software to be registered is located the full path to the software is required, and must be enclosed in quotes. An alternative would be to run the "path" command separately to establish a path to the software to be registered before running regsvr32.

Finally, this is not a hardware problem, strictly speaking. I'll see if I can move the thread to a more appropriate location where someone more expert in these things can help you.

(This posting has been edited to include reference to MS article 277964 and add information about the regsvr32 command syntax shown. )

Manual registration of system components with regsvr32 is reported at one interesting forum thread to require the path to the software component being registered be enclosed in quotes, for instance:

regsvr32 "%root%\[path]\quartz.dll"
instead of:
regsvr32 %root%\[path]\quartz.dll

(The syntax in my earlier posting, as quoted, was mistaken - and has now been corrected.)