You will want to go to your Blood folder and double click on the nblood.exe. You can also right-click on nblood.exe and pin it to your start menu. When you first run it, Windows may pop up a window that states "Windows protected your PC". If you are cautious about running exes you downloaded off the internet (and you should be) you can upload nblood.exe to https://www.virustotal.com to scan it against the various antivirus vendors. To get past the "Windows protected your PC" screen look for a "More info" link and click the "Run anyway" button.