In Windows OS, the automatic windows defender may drastically increase loading times for your libraries, even if you have performed a batch re-save. This is because Windows Defender automatically scans all files and samples as they are being loaded into Kontakt.
To improve your loading times in Windows, you will first need to add your libraries as an exclusion in Windows Defender. Microsoft has an article available HERE to help you get this set up.
Once the exclusion is made, you can perform a batch re-save on your libraries for a significant improvement in their loading speed.
A Batch Re-save tutorial can be found here.