Thank you for additional information Mike.
Because none of the previous solutions works, the next troubleshooting step will be to perform factory reset.
Don't worry, none of your books will be lost. All books are stored (and safe) on cloud.
For newer Kindle Fire devices use the procedure below:
1. Slide down from the top to the bottom
2. Tap "More"
3. On the Settings screen tap "Device"
4. At the very bottom you'll see the option, "Reset to Factory Defaults". Underneath it says, "Removes all personal data from your device."
5. When "Factory Data Reset" warning box opens up select "Yes".
For older Kindle Fire models use the procedure below:
1. Tap on the gear symbol in the upper right corner of the Kindle screen. Select "More..."
2. Scroll down until you see the word "Device." Select this by tapping on the screen.
3. Scroll through the "Device" settings menu until you see the words "Reset to Factory Defaults.". Tap that option.
4. Select "Erase everything." You will be asked if you really want to perform the action of resetting your device to factory defaults. In order to confirm your decision, you will need to tap on the screen over the words "Erase everything."
When done, if prompted de-register your device with the same Amazon account information and try to connect your Kindle to wifi.
Just in case, I'll provide you with procedure how to check your wifi password ***** your laptop. Here is a step by step instruction:1.
Click the wifi strength indicator on the taskbar at the bottom right corner of your computer.2.
Right-click on your wifi network name, and select "Properties".3.
Select "Show characters" to display the wifi network password.
Let me know if this helps please. I'll be waiting for your reply and happy to help with any follow up questions.