@Windows Vista Welcome to MSFN forums
Yandex.Browser already covered in the first post of this thread:
The link provided in that first post, as well as the link one gets when visiting
https://browser.yandex.com/
with an XP/Vista User Agent string (*NT 5.x*/*NT 6.0*) is for a stub (on-line) installer!
Official download link for off-line (Full/Standalone) installer, for version 17.4.1.1026:
http://download.cdn.yandex.net/browser/update/17_4_1_1026_2644_w_s_m/yandex.exe
17.4.1.1026 is built on Chromium 57.0.2987.1026 source and is the last officially supported version on Vista; however, it is not the latest version that can be reliably run on Vista (but not XP); that one is version 17.6.0.1633, built on Chromium 58.0.3029.1633 source:
Most sadly, it has proven impossible to locate a stub and/or full installer for that version, thankfully a third party portable (PAF) package has been archived in SourceForge (and is the one used here ):
https://sourceforge.net/projects/thumbapps/files/Internet/Yandex%20Browser/YandexPortable_17.6.0.1633_on_Chrome_58.0.3029.1633.paf.exe/download
Considering latest Yandex.Browser (19.6.1.153) is based on Chromium 74.0.3729.15 source, version 17.6.0.1633 should be considered deprecated/insecure by today's web standards; be that as it may, I find most websites render OK, with the exception, of course, of github.com (since they insist on always using the cutting edge version of Javascript code); if you spoof your UA to being FirefoxESR 60.x.x, even github works OK (but I suspect this hack will soon break, as FxESR60 will reach EoL towards the end of this month...).
Cheers