The Lenovo does have a usb 3.0 port and are you using that port? What are the hard drives? because if one pc has a really slow drive. (4500 rpm platter ) and the other has an ssd, you would see a major difference in how fast the usb is writing to the drive you have
yes it does have USB 3.0 but its already in use. anyways the USB flash drive is USB 2.0 other flash drives that i have work fine on all computers. the lenovo has sata 600 ssd and the netbook has a sata 150 hdd but it shouldnt matter as i am making copie of file that is stored in the flash drive into the flash drive itself.
What do you have in the 3.0 port? although your only using a 2.0 drive you will get better speed from a 2.0 drive if it is in a 3.0 port, The pc will cache some of the data even if your transferring to the same drive and if the pc is running slow or other apps it will make a difference also. I do not know why you want to transfer the data from the usb back on the usb?
I have a western Digital External HDD connected to USB 3.0. I did "transfer" data from the usb back on the usb to show how slow and unusable it is in one of my computers. doesnt matter of i copy from internal SSD to USB Flash Drive it will always be super slow and get often stuck at 0 bytes/s
the difference is the OS slower on the latest and faster on the older OS could be a driver issue....or if u have another USB HD cable to try it with on the slow machine and see it speed it up.