ASUS T100TA - How I can install Windows 7

Question

I need to install Windows 7 on my ASUS T100TA which has a 32-bit EFI without Legacy Boot option. Windows 8.1 is very lagging, so why don't try install Windows 7?

First, I prepared 32-bit Windows 7 install USB, entered into BIOS, disabled Secure Boot, but the USb didn't boot.

I also tried other way: Created Windows PE 5.1 bootable USB with extracted Windows 7 ISO which successfully booted. I then opened Command Prompt and ran Windows 7 setup, accepted license, selected "Custom install", deleted ALL partitions from 32GB Flash drive, created new partition, but it can't install Windows 7 there (missing Intel SD Host Controller driver).

Can anybody help me unlock the Legacy Boot option or give me the BIOS-emulation bootloader?

Solution

Windows 7 needs BIOS INT10 to boot, in turn requiring CSM.

So, your only choice if you don't want Windows 8/10 is Linux. No need to even disable Secure Boot thanks to the Linux foundation shim most distros ship with.

There are also reported hacks to make 64 bit OS load.

EDIT: it turns actually out there exists hacks for booting without CSM!
EDIT2: UefiSeven has you covered completely now.

EDIT3: duh, the bay trail tablet has a 32-bit firmware, right. And that means W7 requires some extra meddling to work.

Comments

[Admin]

AFAIK, there's no way to add BIOS/CSM/legacy support to a firmware that lacks that support, short of replacing the firmware. Even if you did that, it wouldn't help with driver support issues, which is your problem. To that end, you should check with ASUS, or with whoever made the controller for your "disk" (really flash storage) device. Even if you get this support, AFAIK Windows 7 won't work well on a tablet because of user interface issues. Personally, I'd stick with Windows 8, return the computer for a refund/replacement, or maybe look into running Android on it.

[Admin]

I did clean Windows 8.1 install (not recovery), installed all drivers from ASUS website, installed Office, Windows updates and Chrome, It works well (better than ASUS pre-installed Windows copy), yesterday I tried install Ubuntu 15.10, but no success (booted into "Try Ubuntu", updated grub via terminal, started setup, but after create user account setup hang, after 20 minutes I got "read error" message.

[bertieb]

I could be reading wrong, but this seems to contradict information given in another answer, which suggests you can indeed install Windows 7 64 bit. Can you elaborate?

[mirh]

Other answers say that if you have CSM/legacy it will work. I'm just observing this simply isn't here (bar.. I dunno, you rewriting the bios or something) and ultimately summing up the alternatives then.

[bertieb]

Okay fair enough, I didn't see a mention of CSM in Hennes' answer. I'm not sure "install Linux" answers the question of "how to install Windows 7?"! However, if there are 'reported hacks', they should be summarised here in case the link goes dead :)

[mirh]

"No you can't" technically is an answer. Then actually nothing is impossible, but I think I'd go OT then. And same into mentioning hacks OP may or may not be interested in (after all, I'm just talking after an hypothesis I made of his needs). They are archived on wayback machine anyway.

[bertieb]

Not being able to is a valid answer but another answer says that you can, which I why i suggested clarification. The help centre also suggests including context from a link; "Always quote the most relevant part of an important link, in case the target site is unreachable or goes permanently offline."

[mirh]

You are right, but the thing is that's incidental to the thread. He didn't asked for 64 bit support. I just trivially provided that info to correct him.

[bertieb]

You make an interesting point, so I asked a meta question about it :)

[mirh]

Cool, kudos for the assiduity. Also GG for compliments to me.