Fix broken link CE to PE upgrade (#2374)

* Fix broken link
Upgrade from CE to PE.

* Remove outdated install thingsboard command
from Hello World page

Author: idealissst

_includes/templates/prerequisites.md

@@ -2,25 +2,4 @@
 
 You will need to have ThingsBoard server up and running. 
 The easiest way is to use [Live Demo](https://demo.thingsboard.io/signup){:target="_blank"} server.
-
-The alternative option is to install ThingsBoard using the [installation guide](/docs/user-guide/install/installation-options/){:target="_blank"}:
-- **Windows** users should follow this [guide](/docs/user-guide/install/docker-windows/){:target="_blank"}
-- **Linux** users with Docker installed can execute the following commands:
-
-```
-mkdir -p ~/.mytb-data && sudo chown -R 799:799 ~/.mytb-data
-mkdir -p ~/.mytb-logs && sudo chown -R 799:799 ~/.mytb-logs
-docker run -it -p 8080:9090 -p 7070:7070 -p 1883:1883 -p 5683-5688:5683-5688/udp -v ~/.mytb-data:/data \
--v ~/.mytb-logs:/var/log/thingsboard --name mytb --restart always thingsboard/tb-postgres
-``` 
-{: .copy-code}
-
-These commands install ThingsBoard and load demo data and accounts.
-
-The ThingsBoard UI will be available at: **http://localhost:8080**.
-
-You can use:
-- Username: **[email protected]**
-- Password: **tenant**
-
-[More information about the demo account](/docs/samples/demo-account/){:target="_blank"}.
+Alternatively, you can install ThingsBoard using the [installation guide](/docs/user-guide/install/installation-options/){:target="_blank"}.

docs/user-guide/install/pe/upgrade-instructions.md

@@ -2388,7 +2388,7 @@ These upgrade steps are applicable for the latest ThingsBoard Community Edition
 
 #### ThingsBoard PE package download
 
-Download and extract ThingsBoard PE installation package for Windows: [thingsboard-windows-setup-{{ site.release.pe_ver }}.zip](https://dist.thingsboard.io/thingsboard-windows-setup-{{ site.release.pe_ver }}.zip).
+Download ThingsBoard PE installation package for Windows: [thingsboard-windows-setup-{{ site.release.pe_ver }}.exe](https://dist.thingsboard.io/thingsboard-windows-setup-{{ site.release.pe_ver }}.exe).
 
 #### ThingsBoard PE service upgrade
 
@@ -2400,7 +2400,7 @@ net stop thingsboard
 {: .copy-code}
 
 * Make a backup of previous ThingsBoard CE configuration located in \<ThingsBoard install dir\>\conf (for ex. C:\thingsboard\conf).
-* Copy content of the **thingsboard-windows-setup-{{ site.release.pe_ver }}.zip** to the same location.
+* Run the **thingsboard-windows-setup-{{ site.release.pe_ver }}.exe**.
 * Compare and merge your old ThingsBoard configuration files (from the backup you made in the first step) with new ones.
 * Configure Professional Edition license key as described [here](/docs/user-guide/install/pe/windows/#step-3-obtain-and-configure-license-key).
 * Finally, run **upgrade.bat** script to upgrade ThingsBoard to the new version.