[pjc50]

There are a number of good things about CreateProcess, but argument passing is not one of them. It's a very longstanding misfeature in the design of CMD.EXE and almost certainly dates from MSDOS and therefore CP/M.

A side effect of that is that programs do their own unescaping. Unix users who are used to quotes being stripped for them may be surprised by this.

[timrobinson333]

Many windows programmers fail to appreciate this. If you're using a language that provides argv-style functionality, the quoting and escaping mechanism is entirely at the mercy of that language, so you can't reliably make any general assumptions about how to quote parameters to a command line

[account42]

And specifically, Microsoft themselves can't even agree on the rules so Win32 API CommandLineToArgv and and the MSVCRT have slightly different quoting/escaping rules.