How do I reinstall AVG Internet Security?

Every time (until yesterday) I start my computer, All the AVG things that protect me would pop up. 
Then all of a sudden, I noticed that only 3 things popped up and it said I was not protected.
Opening AVG and clicking on 'Fix Performance' did nothing.
Eventually, I uninstalled AVG completely, figuring it would be an easy matter to reinstall it.
Ha!!!
What a mistake THAT was!!
Sigh.
I have the paid version – I believe it says Performance Pro when I open it.  (Well, it used to say that, anyway.)
Now, I followed the activation instructions that I received last November, chose to find what program I wanted by plugging in my still current License Key and attempted to download the recommended version.
That's when the trouble starts.
I get an error message (and using it to try to find further information proves fruitless.)
The error message contains the following:

AVG Internet Security
Error message:  0xC0070643
General internal error
Additional message:
MSI Engine failed to install the product @AVGMS1_27028
Writing config value failed 0xE001003E
Context:  AVG product installation, MSI action failed

While we're at it, I also had PC TuneUp and for a while (before giving up and trying the above) I tried to reinstall that, also unsuccessfully.
The message I got for that was 'Unknown issues 0xe001p632'.

So what I would appreciate from you is … HELP!!!  Save me!!!  Please!!!
What on earth should I do!!?

Oh!!  And by the way, after totally eradication poor AVG from my computer (assuming I DID manage to do that!), I remembered that I bought a rescue disc and smugly tried to solve things by using that!!
No go.  Got the same error message or one very like it.


Hello Carla. I am sorry to hear about the inconvenience caused. Have you uninstalled AVG completely including AVG Zen? Could you please check and confirm that you have no AVG applications listed in your control panel?

Hello Carla. I am sorry to hear about the inconvenience caused. Have you uninstalled AVG completely including AVG Zen? Could you please check and confirm that you have no AVG applications listed in your control panel?