Calculator: 13s Octave GUI: 5s

The worst thing is that the calculator pretends to be running after like 2s but is unresponsive.

[1] If you can't remember the shortcuts for some of the more obscure functions – never mind that they're also badly documented and you have to find the list of shortcuts by searching for them yourself on the web. I have a memory that way back – possibly not even in Windows 7, but only XP – the calculator included an offline help with all the keyboard shortcuts listed. Nowadays the Windows 10 calculator doesn't include any sort of help at all, not even a link to the online help.

Ouch! I hope you mean Excel 2010 or earlier; all the later ones are so slow to launch or open document that I tend to leave Excel and files (that I'll need to access quickly) open until something forces a reboot or until I bork Excel's state by QAing or triaging somebody's unfortunate VBA (sometimes even mine, too; shhh!). This remained true on a performant gaming computer while working from home. It was always a delight, remoting into somebody's machine that still had a functional Excel 2010 on it.