Vista - dvd doesn't play

Up until last week everything was ok. Now the drive doesn't see dvds, asks to insert the disc (the disc is already there). No problems with cd roms though. Any hints very much appreciated!

You can delete the upper and lower filters and it might help.
start menu-in search type in regedit.
Go to HKEY LOCAL MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11 CE-BFC1-08002BE10318} and if you have entries named Upperfilters and lower filters, then right click on those and delete them. Restart your computer.

Make a backup copy of your registry before attempting to do that and only delete the filters found in that part of the folders. I totally botched my laptop and was not able to load Windows after that.

If you removed phrases UpperFilter,LowerFilter for any another device it's no strange you crashed your system.Not for all devices these phrases are wrong although there are many programs which modify UpperFilter,LowerFilter for many devices but in these situation you have to restore original value for UpperFilter,LowerFilter and not completly remove them.For DVD yes ->UpperFilter,LowerFilter are completly wrong.

Thank you! I did that, but there are no such entries there. Should I check also 0000 subfolder and Properties? I cannot access Properties

There are no these phrases in these subkeys besides only SYSTEM account have access to this keys -but it not concern.

Try this:
Open device manager find DVD ,uninstall driver for DVD and restart computer.Then restart computer again open device manager and reinstall drive for DVD

Dziekuje za pomoc / Thank you, I'll try that. Funny thing isthat after my last post I popped in dvd and the drive recognised it for like 3 min, and then it just stopped again ....

you can try to reinstall the drive again .. download the software that compatible with your drive...

Thank you, I have tried that. I went into device manager and de-installed it. Than I have restarted my laptop. No change. Device manager says that the device is working correctly. Is there anything else I can do?

Updating drivers no help also?Sometimes this trouble may be ralated with any autoplay trouble - some stupid DVD required especially autoplay settings to work properly
Try this tool ->Removing unwanted AutoPlay Handlers in Windows XP and Windows Vista

any reasons:
It may be also caused conflict with virtuals like Alcohol,Deamon Tools...If Clean Handlers no help and you have these kind of programs -uninstall them.

EDIT

Navigate to key HKLM\System\CurrentControlSet\Services\CdRom
and check you have phrase AutoRun is set to 1 one per hundred DVD requires this setting obligatory -if is 0 fix it + restart