Thanks but I was really hoping for a faster solution.
Chances are, you will have to reinstall Win 8 and start from there again.
However, I'd like to point a few things out to you.......
1. RE :
Uninstall button was missing from the interface
I have Win 8.1 Pro. Uninstall button does not appear
until you select an item.
2. RE : Right-clicking an item and selecting
uninstall from the menu gives a warning message suggesting that the application might have already been uninstalled
There are programs there are NOT compatible with Win 8.1, such as older versions of Avast. When Win 8.1 is installed, those that are incompatible will NOT get installed.
Although the Programs and Features still lists those programs, physically they are not present in the system. Hence you receive that error message.
3. RE : it told my that some system files are missing
Wonder if it is "missing" literally, or "corrupted".
Why don't you do a system file check and see what it tells you. System File Check is to look for corrupt files. If it finds any, it will try to do repair.
When it is done, it will give you a report which will say one of the followings. Paraphrasing ......
..... no integrity violation
..... found corrupt files and repair successfully
..... found corrupt files but unable to repair.
How to do system file check....
on your win 8.1 desktop, press Win logo key + X key > at the popup box, select Command prompt
(admin) > at the flashing prompt, copy and paste this command line......
sfc /scannow
press Enter.
It will take quite a while.
If it says it has found and successfully repaired the corrupt files, try the Win 8.1 again.
3. RE : the article
You overlooked the last 2 paragraphs.
excerpt :
Not much, actually, unless of course you do have a Windows 8.1 product key.......
This version of Windows 8.1 Setup prompts for a Windows 8.1 product key, and your Windows 8 product key—from a PC, MSDN/TechNet, or a retail version—will not work.
4. RE : recovery disk
Win 8.1 has the features whereby you can create Repair disk and Recovery Disk.
It also has a feature to do System Image Backup which I do it regularly, about once a week. I had a problem once and I used it to restore a working system.
But those aren't any good to you if your Win 8.1 is a faulty install.