Q:

Microsoft Office 2010 Word not saving

I create a new file on Word 2010. I type a few words. Then I press Ctrl + S to save it or click on the diskette icon on the toolbar. But Word does not save. Does nothing. When I want to close the file clicking the X button of the window, it prompts me if I want to save the changes or not.
Then I have uninstall MS Office 2010 and installed MS Office 2013. I wanted to understand if the problem is sourced by wrong configuration and/or settings. But NO!
The same problem persists on MS Office 2013 Std too.
I have searched for similar problems on Google, but found no helpful solution. I think it is a macro virus but do not know how to overcome it.
UPDATE by Art Gertner:
Experiencing identical problem. Excel and PowerPoint also affected. Attempted the following:

Restarting PC
Deleting Normal.dot
Starting in safe mode (winword /safe)
Disabling all addons
Cleaning up c:/temp
Checking Office activation status (shows valid license)
Checking that default file location in word (options > save > default file location) is valid path
Creating a new user account (issue is still present)
Checking the file system with chkdsk /r (no effect)

Additional details:

OS: Windows 7 x64 pro. Office 2010
Disk encryption is not used
the issue used to be intermittent for several days. Used to disappear after restart. Now it is permanent. Cannot save documents at all.
File > Open and File > save actions are also affected (nothing happens when clicked)
The following workaround is valid. Use windows explorer to navigate to directory where you want to save the file. Right click to call context menu. Select New > Microsoft Word Document. Document is created. Any changes to this document will be successfully saved.

A:

The Only answer I could find for this problem was to create a new user account and move data over.
My customer said:

It was random initially and then became frequent and then permanent and then spread from MS Office products to other programs as well.

Creating a new user account might not be the most ideal thing for everyone but I had to give up & move on at some point. :( looser 
Different stuffs I tried in two days are below:

Not only disable the add-ins but uninstall programs which had any add-in for Office Apps like Mcafee & Lexmark printer toolbar
Clean boot the computer
Plug HDD to a different computer and run virus/malware scans
Tried Office apps in safe mode for sure
Disconnect Network drives as I have seen them causing problem with file Save & Open action at times in past
Played around with Process Monitor, compared then deleted and re-created following registry keys with another similar system.
HKCU\Software\Microsoft\Office\16.0\Common\OpenFind\MicrosoftWord\Settings\SaveAs
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\CIDSave
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32
Ran chkdsk /r
Re-installed MS Office too
No component store corruption detected on DISM /CheckHealth & /ScanHealth
Didn't try System File Checker because I haven't been lucky with it ever

Affected system was a Windows 10 with Office 2013 installed, Which I upgraded to Office 16 later and the problem was still there until a new User account was created

A:

Try running a c:\>sfc /scannow
The comdlg32.dll may be corrupted. This DLL  gets referenced when you want to open or save a document in Office.

