What should I take care of when uninstalling DSE?

Make sure you think twice before deleting the Data folder, located in C:\ProgramData\DesignSpark Electricaldata 

You'd only want to do this if you are never going to use DSE again and don't need your past projects anymore.

Generally, we advise clicking 'no' to deleting the data folder.

Also, retain a backup copy elsewhere of the Projects folder before uninstalling: C:\ProgramData\DesignSpark Electricaldata\Projects 

You can always change the path of the Project folder inside DSE, so it reads from the new location where you backed it up.

Alternate option to backup project data, settings, etc.:

Before uninstalling, you can use the 'Archive Environment' to save everything to a single TEWZIP and keep it safe. You can restore the folder structure later using 'unarchive environment' which will extract the TEWZIP for you.