Although the front-end website is gone, Microsoft still hosts some legacy files on their download.microsoft.com CDN. The direct link for the Serbian Latin LIP was:

Select . Once the search is finished, look for Optional updates are available . Scroll down to the Windows 7 Language Packs section. Find Serbian (Latin) , check the box, and click OK . Click Install updates to begin the process. Method 2: Manual Download (Official Archives)