Install Spellcheck for Notepad++ on Windows

Download Aspell: Visit Aspell’s web site here, download the full installer, and at least one precompiled dictionary. Make sure you are installing the win32 versions of each file.
     
Install Aspell: Now double click on the Aspell full installer which will be titled something like 
Aspell-0-50-3-3-Setup.exe. This will launch the installer and you will have to click Next a few times and choose what icons you also want installed. Keep the default location for the installation which will be C:\Program Files\Aspell.
 
Install Dictionary: Now double click on the precompiled dictionary you have downloaded which in my case was the English dictionary and the file name was Aspell-en-0.50-2-3.exe. This will install an English dictionary into Aspell and allow you to start using it. You can install multiple dictionaries if you would like to spellcheck in multiple languages.
   
 Configure Notepad++: Now click on Notepad++ and it will ask the location of Aspell so type the following into the location field minus the quotes, “C:\Program Files\Aspell\bin”.
     

Test Spellcheck: Now restart Notepad++, enter some text into a new file, and click the spellcheck button to see if it is working.