Launch NTLite. Click Add > Image Folder and point the program to C:\Win81OS . Select your specific OS edition (e.g., Windows 8.1 Pro) from the list, right-click it, and choose Mount .
: Community ISOs are not verified by Microsoft. They may contain malware or modified system files. It is safer to download an original ISO and manually apply updates using tools like the Microsoft Update Catalog Installation & Configuration windows 8.1 fully updated iso
(if still available for 8.1)