Complete the items on the checklist below to troubleshoot this issue:
Use only the Username/Password/License Key generated for you and sent to the email address you provided while registering/purchasing a license. For example:
Copy/paste your Username and Password, or License Key (depending on product version) into the activation screen and be sure not to select an extra blank space.
If you cannot copy/paste, type your Username and Password, or License Key, EXACTLY as they are written:
If your Username and Password, or License Key still do not work:
Clear the update cache in your ESET Windows home product. Click to view instructions.