That "More Options" in Disk Cleanup should only have removed 'all but the latest' System Restore point, so if that latest point is before all these changes took place, restoring to that might work.
Other options;
1] Reinstall the DVD software you had previously installed.
2] Download and install the VLC Player which doesn't need codecs and plays DVDs.
Mark
When I put a DVD into CD/DVD tray Windows media player comes up a window in center says "Windows media player can not play DVD because a compatible dvd decoder is not installed on your computer" Last week it played, but yesterday my brother tried to update his i phone which lead to 8 hours of him and an apple tech trying to figure why his phone would not update blaming everything from avg free software to Malwarebytes software and I have no idea what else. Both these items were uninstalled and Microsoft security essentials was downloaded. I honestly don't know what my brother and the apple tech all did but the result is I can no longer watch a DVD. When I click web help from the error window it sends me here: http://windows.microsoft.com/en-US/windows/help/windows-media-player/dvd-codecs?locale=409&geoid=f4&version=11.0.5721.5280&userlocale=409 it tells me to buy a compatible plugin. I would just restore to an earlier date but a disk clean-up was done and yes went to more options and did a systems restore clean-up too. I have XP pro OS on a HP Compaq Presario SR 1617cl PC. Is there anyway I can fix this short of buying a plug in or even a recovery to play DVD with WMP? Any help or ideas would be appreciated thank you

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic