To make a portable clone of your qbittorrent, make a new folder, "X", anywhere, and copy qbittorrent.exe and qbittorrent.pdb into X.
Then create a "profile" folder inside X.
Now you could run X/qbittorrent.exe, and it would create the folder X/profile and populate it.
BUT, what if you want to clone your existing qbittorrent's config and torrents?
The documentation of portable mode for Windows says, "Note: You can copy qBittorrent configuration files from any installation, portable or not, to the matching directories inside the profile directory."
BUT, there are at least two different qBittorrent configuration directories:
C:\Users\<user>\AppData\Roaming\qBittorrent
C:\Users\<user>\AppData\Local\qBittorrent
The docs don't say which config directory to copy into the profile directory.
The answer is, Both! But don't just drag-n-drop each of those into the profile directory; it won't work.
Run X/qbittorrent.exe, & it will build a config in X/profile/qBittorrent, with 3 subdirectories:
cache (this will be empty)
config (this corresponds to C:\Users\<user>\AppData\Roaming\qBittorrent)
data (this corresponds to C:\Users\<user>\AppData\Local\qBittorrent)
So to clone your installed qbittorrent to a portable one,
copy the contents of C:\Users\<user>\AppData\Roaming\qBittorrent into X/profile/config
copy the contents of C:\Users\<user>\AppData\Local\qBittorrent into X/profile/data
BUT, don't copy the config directory from a different qbittorrent version! It probably uses different parameter names.
ALSO, if you copy the config, you'll end up with both qbittorrents using the same port.
You don't want that. Change one of them.
If you run it first with no profile folder, it will generate a default profile folder, and a config
with a randomly-chosen port, so you don't have to worry about it.
and a config with a randomly-chosen port.