These days I'm doing some research, and I found some very interesting.

In Longhorn early builds (3683-3718) there is one file in i386\ TestRoot.cer - this is a certification file.
This file contain bios clock settings.

I've tried to remove it, but I don't have any success.
When file name is removed from TXTSetup.sif, you get: Fatal Error 800b0100 Signature error. Catalog file cannot be write in Root store.

However If some one can solve how to skip this, we'll get a biosclock free OS.

I am going to make an attempt.
Edit: It failed.

Is it possible to simply edit the information INSIDE testroot.cer?

The only way I can think of to that is to hex edit it.....

Couldn't you just edit setupreg.hiv instead, as I remember?

Setupreg.hiv is used for nuking the timebomb prior to installation. It sounds like TestRoot.cer is responsible for the out-of-date product catalog error you get if you try to install Windows from within Windows without setting the BIOS date back.

I won't tell you. You'll have to find out yourself.

Isn't it always NT5.CAT that determines the timebomb in i386 setups? Basically, it's valid for one year after build, and that certificate must be valid for the install to succeed.

That's what I remember from earlier discussion anyway.

I found testroot.cer in two more files (Dosnet.inf; Layout.inf ), and I remove it from there to, but still no success