What would cause W7 DVD to not boot on old PC?

This is more a matter of curiosity for me than anything else.

I have an old P3/866 with 512MB RAM that works fine with Ubuntu (doesn't get much use these days, admittedly) and I thought I'd fire up W7 just to see how it performs. I quickly grew frustrated by my inability to boot from the W7 32-bit disks... 7000, 7057 builds alike.

At first I thought I was burning coasters, but the disks I burned booted fine on other more modern computers.

Then I thought maybe the DVD reader on that old computer was just too old / buggy / couldn't read my newer DVD-Rs. So I swapped in one from a much newer PC that I know could read these disks (indeed, I used the newer one to burn them) but no luck.

Then I thought maybe it was due to some problem with the PC. So I grabbed some bootable CDs and DVDs (retail pressed Windows discs) and this old P3 did boot those disks just fine.

Then I thought maybe it's something weird about that drive and my DVD-Rs in that old computer. So I moved that drive back to another PC, burned a DVD of Windows Home Server (had an ISO handy), moved the drive back to the old computer, and lo and behold, the WHS install disc boots on this old P3 just fine.

I grabbed a Windows 2008 ISO and it too boots on this old P3... won't install, of course, but at least it boots!

But not the W7 32-bit disc. It spins, the drive reads it, then proceeds to boot right off the HD. It's like the W7 bootstrap is saying "sorry, can't proceed but can't tell you why either" then kicking off the HD boot.

Any ideas? This is more a matter of curiosity at this point, I'm quite happy with my i7 running W7... I was just interested in how it would perform on this old but reliable hunker and am surprised by this finding.

(BTW the hunker is an old "Dell Dimension 4100" if anyone cares...)

The disks I was burning booted fine on other more modern computers, so I thought

 

it's less than 1.ghz on the processor side
less than 533mhz fsb will do
less than 1mb l2 cache will not be able to boot also

 

Are you suggesting that the bootstrap code checks the processor ID and skips the install sequence if the reported clock speed is less than 1 GHz?

I suppose that's possible, though I would not have expected that sort of code...

 

my experience is even weird,my c2d t7100 is taken as single core single threaded processor in win7 7000.

how do we beat this?

 

I recently had this problem when I upgraded to Win7 from Vista with RMclock installed. RMclock somehow caused Win7 to believe I only have a single processor in a multi processor environment and no matter what I did I couldn't get it right. I reverted back to Vista using a complete PC restore and removed RMclock before re upgrading to Win7. Works fine now.

 

i dint even had any cpu software installed.
so u suggest reinstall of os?

 

less than533mhz will boot. Many netbook user run w7. intel atom has 512kb l2 cache.

 

I've still been trying to figure this out. I was wondering where you found this information... does the installer CD check the above and not even try to boot if the above requirements aren't met?

This strikes me as a very odd thing to do; not meeting the above specs will slow things down, but they shouldn't impair basic functionality.

I've definitely confirmed that at least two old P3/512MB/866-and-933MHz PCs simply will not boot the DVD at all, though they certainly will boot a variety of other operating systems, even Vista 32-bit SP1, without a problem.

 

Ditto with 7100.