WinToUSB Pro 8 has 3 functions: create a Windows to go drive with either a fresh [new] copy of Windows 10 or 11, or using one you have already installed; create a bootable USB stick to install Windows on a PC/laptop; and create a bootable USB stick containing a generic copy of WinPE, the minimal version of Windows that allows bootable USB sticks from backup & partition apps etc. to work.
That last option however, creating WinPE USB sticks, does not really work, at least not how you'd imagine it *should* work. It Won't create a WinPE anything -- for that you still have to download and install the 2+GB Windows ADK -- but if you already have a WinPE ISO, say from one of Hasleo's other apps, WinToUSB Pro will happily put it on a USB stick for you.
The 2nd option, creating a Windows setup USB stick, can already be handled with the Windows Media Creation Tool that you can download from Microsoft[.]com. Rufus can do the same thing -- it's a small, free, & extremely popular app that's also available in a portable version. So can Ventoy, which lets you add multiple ISOs to the same USB stick, e.g. setup files for both Win10 & 11.
That leaves putting Windows on a USB drive, which is what the app is mainly good for. While it says it'll work with Win7, Win10 is/was the first version of Windows that would really work on a USB drive -- there are some hacks that sorta work, more or less, but Win10 was the 1st to work fully as you'd expect it to, plus, Win7 installs needed drivers once, when 1st installed [Win10 & 11 will check at every startup], so migrating a copy of Win7 to a USB drive is only good on the hardware it was originally installed on. Those drivers have to be turned off for Win7 to work on new hardware, and that only works some of the time.
You can also create a Windows To Go drive with Rufus, or using AOMEI Partition Assistant. With the upcoming change to Windows boot files [Microsoft now says it won't be here until July, 2024 at the earliest], the frequently updated Rufus *may* be the best choice as that change gets near, if that matters to you.
support.microsoft[.]com/en-us/topic/kb5025885-how-to-manage-the-windows-boot-manager-revocations-for-secure-boot-changes-associated-with-cve-2023-24932-41a975df-beb2-40c1-99a3-b3ff139f832d
I tried creating a WinToGo drive on a troublesome SSD I had in a desk drawer, connected via a Sabrent HDD to USB 3 adapter. WinToUSB Pro offered to give me a download link from microsoft[.]com, but I just downloaded a Win11 ISO directly instead. Since I wanted to test it with my VM I 1st chose to create it in the VHDX format, but that resulted in 2 partitions, the boot partition and a partition with the VHDX file, so it didn't really help -- I wanted a single VHD or VHDX file containing both partitions. You get your choice of VHD, VHDX, or legacy [regular HDD] which I chose next. Then I backed up the SSD, restoring that backup to a new VHD drive I created [Computer Management -> Disk Management]. Detaching [unmounting] the VHD in Windows, I used it to replace the drives in my Win11 VMs and tried to start Windows. Since it used the boot files from the latest official Win11 ISO I was curious if it would boot to the Win11 VM with secure boot, TPM, and the new boot file mitigations enabled -- it would not work. Using my Win11 VM with legacy rather than UEFI booting [no secure boot etc.] it worked fine. Since it's using all the boot files from the Win11 ISO it should work for UEFI and secure boot as well. The only other note is that this Win2Go installation uses pagefile.sys & swapfile.sys files -- not all Win2Go installations do.
WinToUSB Pro takes up ~80MB in the program's folder, which is the only folder added. The only registry entries are Windows related, with the exception of one compatibility entry. The Pro version however does not appear to be portable -- it collects a fair amount of data to come up with the Machine Code shown in the About window.
FWIW, IMHO it's worth creating a Windows To Go drive if you troubleshoot & fix Windows &/or PC/laptop hardware. It also works well in place of bootable USB sticks &/or portable apps, especially when whatever app's USB sticks don't work, or when portable versions of software like partition managers aren't available. And it's a decent way to see how Win11 will behave on hardware running Win10 without going to the trouble of installing it. In some situations, running Windows off a USB drive might even be preferable, e.g., completely eliminating access to your stuff when using a shared computer. While it is possible to use a USB stick for a Win 2 Go drive, they're generally FAR too slow, making it painful to use -- use an SSD in an external housing. 120 & 240GB SSDs are incredibly cheap right now, and you can find housings on sale for $5 - $10. FWIW I like to use a Windows Enterprise ISO to create Win 2 Go drives, avoiding any complications regarding activation, effects on activation from changing hardware etc. The limitations from running Windows unactivated are really minimal. It is possible to create a dual or multi-boot Windows to Go drive -- create the individual Win2Go drive, perform a partition image backup, create a 2nd Win2Go drive, reduce the size of the partition, restore the backup to that now unallocated space, and use EasyBCD [or Windows BCDEdit] to add it to the boot menu.
Those are the pros. The cons include... sometimes the changes that are made to Windows to work with particular hardware will mean it won't work on any other hardware from then on -- I've run into this with an Asus motherboard -- so you really do need to have an image backup that you can restore to the drive if you want to use it on other hardware. The driver software that's automatically added can also sometimes cause problems with other hardware, as well as contributing to bloat. And you do have to update your Win2Go drive(s), just as you update regular copies of Windows.