A genuinely portable Windows app can keep its executable and settings in a USB folder and run without a traditional installer. A normally installed program may depend on Registry entries, services, drivers, licensing, and files under Program Files or AppData. Copying its folder to USB does not create those dependencies on another PC. Check the software publisher's portable version and license terms.
Step 1. Download the publisher's portable release from its official site. Avoid “portable” repackages from unknown sites.
Step 2. Extract or install it onto a trusted USB drive with enough free space. Scan the files with Windows Security. Run the executable while signed in as an account allowed to use it.
Step 3. Save test data, close the program fully, safely eject the drive, and test on a second PC. If it asks for an installer, administrator rights, a service, or a license activation, it may not be truly portable.
Running one portable app is different from booting a complete Windows workspace from USB. Microsoft's Windows To Go feature was removed from Windows 10 version 2004 and later; cloning a normal Windows system onto an ordinary flash drive is not a supported general-purpose portable-app method. USB speed, file-system limits, and organizational security controls also matter.
If an app cannot run portably, install it normally on the new PC and transfer its documents or exported settings with the vendor's procedure. You can back up these files with Qiling File Backup, but the backup does not turn a non-portable app into a portable one.
Use publisher-supported portable versions for USB execution. For installed software, reinstall on the destination and transfer supported data or settings separately.