I spent many times to convert my usb disk in a USB disk UEFI Bootable.
I found the right solution in this post:
I’ll copy all post from lenovo site to my site to avoid that information will be lost
Lenovo ThinkPads shipped with Microsoft Windows 8 preloads are configured in UEFI mode. Legacy-based boot media will not boot successfully on Think Branded Lenovo.
The above symptom is associated with, but not limited to, the following systems:
Affected Systems (machine types, model types):
All Operating Systems
Microsoft Windows 7
Microsoft Windows 8
To create UEFI bootable USB media that can be used to install Microsoft Windows 7 or Windows 8 64-bit operating systems on Lenovo Think Branded computers, follow the steps below:
1. Open a Command Prompt with Administrator privileges in either Windows 7 Pro or Windows 8 Pro.
Insert the target USB boot media device into an available USB port.
2. Type “DiskPart” in the command prompt.
3. Type “List Disk” (make note of the disk number of the target USB drive).
4. Type “Select Disk X”, where X is the target USB drive noted in step 4.
5. Type “Clean”.
6. Type “Create Partition Primary”.
7. Type “format FS=fat32 quick”.
8. Type “Active”.
9. Type “Assign”.
10. Type “list volume”.
11. Type “Exit”.
The user should copy the entire contents of the desired operating system onto the newly created UEFI boot media device.
If the AUTORUN.INF file fails to copy from the Windows DVD media to the USB key, then use Notepad to create a new AUTORUN.INF file on the USB boot media by following the steps below:
1. Open the AUTORUN.INF file on the DVD media with Notepad and copy the contents.
2. Create a new file on the USB media with Notepad and paste the contents from step 1.
3. Save the file as “AUTORUN.INF”.
UEFI BIOS requires 64-bit versions of Windows operating systems.
Lenovo ThinkPad Tablet 2 has a 32-bit UEFI BIOS.
A 32-bit version of Windows 8 is required for the ThinkPad Tablet 2.
The USB boot media must be at least 4GB in capacity.
To install Microsoft Windows 7 or Windows 8 in UEFI mode, the 64-bit versions of the respective operating system DVD media will be required. A full Windows 7 or Windows 8 DVD media is required. An upgrade DVD may not function correctly during base operating installs.
To create UEFI bootable USB media that will launch an MDT deploy, follow steps 1 through 12 in the Solution and then follow the steps below:
1. Copy the contents of the \boot folder and the \EFI folder from the Microsoft Windows 8 install DVD to the USB media.
2. Create a folder called “Sources” on the USB media.
3. Copy the LiteTouchPE_x86.wim from the MDT deploy share to the newly created “Sources” folder.
4. Rename the LiteTouchPE_x86.wim to boot.wim.
5. Boot the USB media to begin the MDT deploy.
Lenovo, ThinkCentre, ThinkStation, and ThinkPad are trademarks of the Lenovo Corporation in the United States, other countries, or both.
Microsoft, Windows, and the Windows logo are trademarks, or registered trademarks of Microsoft Corporation in the United States and/or other countries.