The primary danger of using a preactivated ISO from an unofficial source is . To "preactivate" Windows, third-party uploaders often modify system files or include "KMS activators" and scripts. These modifications can easily hide:

that eventually stop working, resulting in "Non-Genuine" watermarks and limited system functionality. No Support

While "All In One Preactivated" versions are convenient, downloading modified operating systems carries risks.

If you see "Download quota exceeded for this file," do this:

It typically offers the maximum bandwidth your ISP allows.

Never install a custom OS on a machine containing sensitive data without a full external backup.