I installed five updates on 15/09/2014. (Updates: KB2995004, KB2993100, KB2990532, KB2979582, KB2975719)
When I tried to print a document today I noticed that my default printer was missing. It appeared in the list of installed Printers (Control Panel) but not the dialog box. I restarted my computer to resolve this issue.
I then noticed that my audio was not working. I clicked the Audio taskbar button and it started to detect and resolve problems however this was unsuccessful. I tried to manually start the Windows Audio service which gave me the following message: "Windows could not start the Windows Audio service on Local Computer. Error 0x800706cc: The endpoint is a duplicate."
I had a feeling that it could have to do with the recent updates I've installed. I tried to open Control Panel but here's the strange part, it says 'Adjust your computer settings' like usual and then the Control Panel freezes and it becomes blank (all text below the navigation disappears). The only way to get rid of the Control Panel window is to restart Windows Explorer through Task Manager (In PC Settings, similar things happened). Then I did a Whole Computer scan with AVG and it found two threats (.exe files related to EID_pe_iscorrupted, not sure if this has any relation).
I booted up safe mode and Control Panel worked fine, I repeated all the steps above with no success. I went to Windows Update and tried uninstalling the updates one at a time, when it restarted it said 'Failure configuring Windows Update Undoing changes'.
Then I went to Computer > Properties (of the C drive) > Tools > Check. I checked for errors and it told me, 'Windows has found errors on this drive that need to be repaired. Close the dialog box and repair the drive'. Then I tried chkdsk /scan in Command Prompt. It told me to do an offlinescanandfix. I did this and restarted the computer. It was checking the disk and started up in safe mode with no sign of successful checking. I checked Event Viewer and there was nothing reported.
I attempted System Restore in Safe Mode, fortunately there was a restore point created on 12/09/2014. Unfortunately when I tried to attempt this it only restarted again, telling me that it failed and gave me the error code: 0x80070570. I attempted this again after a clean boot and going into Properties of Block Level Engine Backup Service. It still gave me the same error code.
I went back into the normal mode and attempted System Restore and Check drive. This time Windows said there were no errors with the drive and System Restore failed once again (same error code). Thankfully networking features are intact but Control Panel, Audio and System Restore are not.
I am quite unsure if it's the recently installed updates or possibly a virus.
System Details:
OS: Windows 8.1
Manufacturer: HP
Model: Pavillion 15-n270ea
I've also posted this on Microsoft Community but I need to get help form other forums.