The software vendor has disabled downloads of all older versions of their software from their official website. I need to downgrade their software to the older version because the latest version is not working in my software environment. is there any way to find older working download links? Cached on some mirror servers or elsewhere?
Here is what I would do to find working download links if their official vendor no longer provides them. The idea is to use Archive.org and see if they have cached those links and if so, you could download from Archive.org and be reasonably sure it is safe to run. So here is the workflow:
Once you know the specific older version of the software you are looking for (like Skype 7.5), use google with keywords like "Skype 7.5 download link" or so. You should be able to figure out an exact link like it may be
http://download.skype.com/msi/SkypeSetup184.108.40.206.msi in case of Skype 7.5. If that link works - just download your software from there, and you are done. However, quite often the problem is that this link is no longer working - vendor has changed their site structure, decided to block older downloads, etc, etc
so using the Skype 7.5 link above, the Archive.org url would become this:
Some examples of this method in practical use to: