That is weird! When I do the same search I get Outlook first and PuTTY second. It's weird PuTTY is coming up at all though?? As an aside, it is possible to disable all the "Search the Web" results if you are interested. I think it's a quick RegEdit but it's been a while since I've done it. Makes the search a ton better though.
I think it's a PowerToys feature, but with it you can press Option+Space (from memory) to bring up a separate search bar, somewhat akin to macOS' Spotlight. That can be more useful and accurate than the standard search.
Putty is first on the result because: is pinned to start menu, or on the most used apps. and the other is ridiculous how MS want to force Bing results on everything.
@impeeza Outlook is also pinned. But the fact it reports Putty instead of Outlook as the first result is ridiculous. Putty as the second result I could get on board with.
*shows a random program as "best match"*
*shows 8 possible web-search results*
*shows what you exactly want to open*
WIndows