UEFI and Lenovo Notes

[Ocelaris]

I've been working to get UEFI working in our environment for the past few weeks and thought I'd share some information; this is on Lenovo hardware, but it's probably applicable across most brands.

 

With some of the newer Lenovo laptops/desktops coming with Windows 8 out of the box, a lot of them come with UEFI turned on and have some really great boot times because of this. So I packaged up these new models for our standard windows 7 64 bit image and then went to work on getting them to work with UEFI and I thought I'd just share some notes.

 

If you haven't checked out Niall's howto already, it's a good place to start.

 

http://www.windows-noob.com/forums/index.php?/topic/6250-how-can-i-deploy-windows-8-in-uefi-mode-using-configuration-manager-2012/

 

UEFI requires a GPT partition, but not all machines are fully compatible with UEFI, so you have to determine if your machine can do UEFI. When you create a generic task sequence (like Niall's walk through), it gives you a nice conditional steps which will check built in OSD task sequence variables _smstsbootUEFI which will tell you if you've booted using UEFI. I found it to be only partially reliable so I ended up doing WMI queries based on model #s, i.e. if model = new then partition in the GPT format. if Model = old partition in MBR format.

 

Another key is that when you lay down your WIM, you should assign it to install to a varible "OSDISK" and you need to make sure to tag your main windows partition in the partitioning as "OSDISK" as well. This should be done in both the BIOS and UEFI partitioning; then you only have to point 1 WIM to either type of image. The same WIM works on UEFI or BIOS, it doesn't matter.

 

Another problem is how to get your machines which support UEFI into UEFI mode. Lenovo gives vbscripts which will allow you to turn various bios settings on/off, some discovery on your part is required; as they are WMI queries, and vary from model to model.

 

Lenovo Bios Scripts:

 

http://support.lenovo.com/en_US/detail.page?LegacyDocID=MIGR-68488

 

The last important piece is that not all hardware components are fully UEFI compliant; by this I mean specifically Lenovo video drivers are not fully UEFI compliant in windows 7. They work 100% in windows 8, but in windows 7 you MUST use CSM or Compatability Support Module. Basically you're not going to get the ultra fast boot times because the video card bios isn't fully supported in windows 7. You have to go to windows 8 to unlock the ultra fast reboot.

 

Lenovo support article explaining that windows 7 is not fully compatible with the intel video.

 

https://forums.lenovo.com/t5/T400-T500-and-newer-T-series/Unable-to-Install-Windows-7-without-CSM-support-enabled-in-BIOS/ta-p/1038089

 

Summary:

 

UEFI is great, but a lot of hardware isn't fully compliant under windows 7 so the benefit just isn't there yet.