Battlefield 4 "origin is not installed [PC]

Even if you tried already to clear your registry from all Origin entries, I would recommend to follow these steps again:

To manually uninstall Origin, you will need to edit your system registry and remove the folders in a two-part process.
NOTE: If you remove Origin, you will lose accessibility and playability to any downloaded games and manuals until you reinstall Origin.

Remember that editing your computer's registry or files incorrectly can severely damage your operating system. We recommend having a computer professional perform these steps. If you are confident, however, that you can edit your registry successfully, then please follow the instructions below carefully.

Remove the Origin program files:

1. From the Start menu, select Computer.
2. Select the hard drive; by default, Origin is installed on the C: drive.
3. Select the Program Files folder; on 64bit systems, this will be called Program Files (x86).
4. Right-click the Origin folder and select Delete.

Backup the Windows registry:

1. Hold down the Windows key and press R.
2. At the Run command, type regedit and select OK.
3. Select File, then Export.
4. Under Export Range, select All.
5. Choose a location and name for the backup file, then select Save.

Remove the Origin registry keys:

1. Expand the HKEY_LOCAL_MACHINE folder.
2. Expand the SOFTWARE folder.
   On 64bit systems, expand the Wow6432node folder.
3. Right-click the Origin folder and select Delete.
4. Expand the Microsoft folder.
5. Expand the Windows folder.
6. Expand the CurrentVersion folder.
7. Expand the Uninstall folder.
8. Right-click the Origin folder and select Delete.

Remove the Origin program cache:

1. From the Start menu, select Computer.
2. Select the C: drive.
3. Select the ProgramData folder.  If this folder does not appear, press Alt, select Tools, then Folder Options.  Select the View tab, then check Show hidden files, folders, and drives.
4. Right-click the Origin folder and select Delete.

The Origin client should now be completely removed from your computer.

After that, launch Windows in safety mode with network support. Download Origin again and start the installer as /administrator.

Please keep us updated.

Cheers

Basti