I have a new Lenovo AIO and I was able to finally get Windows 7 on the hard drive after many hours of trying to inject the usb drivers. It's like WinToUSB somehow crashes access to the stick completely. Interesting thing I found out is, that once the installation reaches 95% you can not open any partitioning tool cause it hangs when trying to read the USB SSD Partitions. But here I have exactly the same problem installation stops at 95%. I then fiddled around and in the end (as my system runs from UEFI disks anyway) I used diskpart to wipe the disk, convert it to gep and create ESP/EFI partition and windows partition (interestingly a 128MB msr partition also got created although I did not opt for that). It seems that it cannot create normal files to boot from. I first tried MBR mode with a small fat32 partition 100MB and a big ntfs partition but the stick always hangs at 95% of the install process (after copying the vhd file I use as starting point). It reports itself as disk so I read the guide on how to prepare the disk in order to use WinToUSB. As my old USB stick was very slow I bought one of the fast GTX Voager USB stick without knowing that this stick is more like a mini external SSD as a normal USB Stick.

Wintousb cannot select boot partition