Apps / Software :: Office Work File Error - Can't Access Temp Internet Folders

I recently installed Windows 8.1 from scratch. After installing Office 2013, I'm getting this error when launching Word: "Word could not create the work file. Check the temp environment variable." If I try to create a new spreadsheet in Excel, I get this error: "Microsoft Excel cannot open or save any more documents because there is not enough available memory or disk space." Memory and disk space are plentiful and definitely not the problem here.

Also, I can't save or open files downloaded with Internet Explorer, which I believe is related (explained below).

I tried running winword.exe /r and re-installing Office, but the problem remains.

I've verified that HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders is set to %USERPROFILE%AppDataLocalMicrosoftWindowsINetCache in the Registry.

Research seems to indicate that the Temporary Internet Files location in Internet Explorer (!) is the likely cause of the problem. Internet Explorer shows the Current location field of Temporary Internet Folders is blank.

I've tried changing/setting the Temporary Internet Files folder to both C:UsersProfileNameAppDataLocalMicrosoftWindowsINetCache and C:UsersProfileNameAppDataLocalMicrosoftWindowsTemporary Internet Files, but I get this error: "Windows is unable to gather information about the location you have chosen. Please select another, or verify that you have access rights to the location." I'm running an Administrator account.

If I try to open either of those folders in Explorer, I get this error: "C:UsersProfileNameAppDataLocalMicrosoftWindowsINetCache is not accessible. Access is denied."

I've tried Taking Ownership of both folders. I've tried removing the Read-Only flag from both folders. I've tried editing the security permissions and adding my specific profile name (Administrators is already there). I still can't access those folders.