Solved Switching to UEFI from Legacy post Windows 8.1 install

[TheCatandThePat]

Hi folks I'm new to the forum and pretty much new to forums in general so I do apologize in advance for being a noob and any potential mistakes I make.

I recently bought a used laptop (Dell 7720) I did a complete fresh install of windows 8.1, including drivers, applications etc. I cloned my HDD to a SSD and now am booting from that and using the HDD as a mass storage.

Since the install I have realized my system is set to boot in Legacy mode but I have recently read there are various benefits from booting in UEFI mode. So what I'm wondering is if the difference is worth making the change and if so what do I need to do to enable UEFI mode?

I understand how to switch from UEFI in the bios but there are other options like boot order etc.

I'm also wondering if I'd be required to re-install and start fresh or if it's as simple as switching modes. Would switching modes create some sort of driver conflict or application conflict ,etc.?

If it's really not worth the switch I'd just as soon leave it alone.

I hope that's enough info to go on and I do appreciate any help. Thanks in advance.

 

[yu gnomi]

My own experience is that if your boot drive is MBR partitioned, and you switch your bios to UEFI mode, you will not be able to boot your OS. You will end up in the UEFI shell instead.

It is conceivable that your OS actually is on a GPT partitioned drive, and your bios is operating in legacy mode anyhow. If you check the Disk Management utility (can find by typing it in windows search bar), you should see at least 4 partitions on your boot drive if it is GPT partitioned (more if you added any yourself). In that case, you only have to switch bios mode to get all UEFI goodness.

If your drive is MBR partitioned, you will probably need to re-install. There are some utilities out there that claim to convert everything from MBR to GPT, but I do not know if they work at all, and I especially don't know if you can use one while your OS is on the drive you are trying to convert.

 

[TheCatandThePat]

OK well, my drive is definitely MBR. I'd rather not trust a program or utility to switch everything. I guess that being said since I'll have to go to the trouble of a fresh install is it even worth doing or are the benefits negligible?

 

[Cliff S]

UEFI BIOS Advantages:

1. When the option is available to choose between a Legacy BIOS boot mode or UEFI boot mode operating system installation, the advantages to choosing a UEFI boot mode installation include the following:
2. Avoids Legacy Option ROM address constraints. For more information, see Legacy BIOS Option ROM Allocation Considerations.
3. Supports operating system boot partitions greater than 2 terabytes (2 TB) in size.
4. PCIe device configuration utilities are integrated with Setup Utility menus. For more information, see BIOS Setup Utility Screen Reference .
5. Bootable operating system images will appear in the boot list as labeled entities, for example Windows boot manager label versus raw device labels.

Benefits of UEFI boot mode over Legacy BIOS boot mode include:

1. Support for hard drive partitions larger than 2 TB
2. Support for more than four partitions on a drive
3. Fast booting
4. Efficient power and system management
5. Robust reliability and fault management

 

[SIW2]

No benefits to mbr?

No drawbacks to EFI?

 

[yu gnomi]

Having operated both on the same system, I would say that there isn't any advantage to MBR.

I couldn't say for certain, but my system might be booting, and waking from sleep, just a little faster now that I am using UEFI / GPT.

 

[TheCatandThePat]

I do appreciate the responses and helpful info. I think I understand (at least partially) the benefits. Anyone care to voice an opinion on if it's worth the pain in the neck of doing a fresh install, keeping in mind I'd have to install all my drivers and programs again.

 

[Cliff S]

No benefits to mbr?

No drawbacks to EFI?

I found this article at Windows Secrets.

 

[yu gnomi]

I do appreciate the responses and helpful info. I think I understand (at least partially) the benefits. Anyone care to voice an opinion on if it's worth the pain in the neck of doing a fresh install, keeping in mind I'd have to install all my drivers and programs again.

I was going to hold off on switching from MBR to GPT until I upgraded to either 8.1 pro (if I ever do that), or Win 10. However, my attempt to install the Win10 preview alongside 8.1, in dual boot fashion, messed everything up. I decided to backup my data and documents, and reinstall Windows and all my programs as well.

I can't say the benefits of UEFI/GPT are really worth the effort, but if you are in need of a weekend project to keep you busy, then go ahead.

 

[TheCatandThePat]

I do appreciate the responses and helpful info. I think I understand (at least partially) the benefits. Anyone care to voice an opinion on if it's worth the pain in the neck of doing a fresh install, keeping in mind I'd have to install all my drivers and programs again.

I was going to hold off on switching from MBR to GPT until I upgraded to either 8.1 pro (if I ever do that), or Win 10. However, my attempt to install the Win10 preview alongside 8.1, in dual boot fashion, messed everything up. I decided to backup my data and documents, and reinstall Windows and all my programs as well.

I can't say the benefits of UEFI/GPT are really worth the effort, but if you are in need of a weekend project to keep you busy, then go ahead.

Ok well I guess I will hold off until 10 comes out or until like you say I feel like having a weekend project. Thanks again

 

[Migotop]

UEFI

I am told that UEFI is a huge preventive mitigation against root kits as well, seems worth the extra key strokes to me...

 

[Cliff S]

I am told that UEFI is a huge preventive mitigation against root kits as well, seems worth the extra key strokes to me...

That only goes for PCs designed for Windows 8 and above that have Safe Boot in the BIOS.

Windows 7 PCs do not have this and the only advantage UEFI can offer a PC designed for Windows 7 is that by default on a basic MBR disk, you can create a maximum of 4 Primary partitions, or3 Primary partitions and 1 Extended partition with up to 128 logical volumes in the extended partition on a single hard disk, and GPT can have 128 partitions.

So if the PC is older the only advantage would be if the OP has a NAS or a HDD larger than 2TB and also wants to create special partitions for DATA or games...etc. without Safe boot or fast boot it's not worth the headache. Also it's better to do a fresh install and then any other secondary disk should be formatted to GPT then also.

 

[Migotop]

I am told that UEFI is a huge preventive mitigation against root kits as well, seems worth the extra key strokes to me...

That only goes for PCs designed for Windows 8 and above that have Safe Boot in the BIOS.

Windows 7 PCs do not have this and the only advantage UEFI can offer a PC designed for Windows 7 is that by default on a basic MBR disk, you can create a maximum of 4 Primary partitions, or3 Primary partitions and 1 Extended partition with up to 128 logical volumes in the extended partition on a single hard disk, and GPT can have 128 partitions.

So if the PC is older the only advantage would be if the OP has a NAS or a HDD larger than 2TB and also wants to create special partitions for DATA or games...etc. without Safe boot or fast boot it's not worth the headache. Also it's better to do a fresh install and then any other secondary disk should be formatted to GPT then also.

This is good to know, thank you! Is there a way to quantize the effectiveness of safe boot? I'd be very interested in stats if they exist somewhere...

 

[Cliff S]

For more on Fast boot.
For more on Safe Boot(actually called Secure Boot).
Both at MSDN Blogs.