BIOS hard disk boot order keeps changing

[mhl]

In a recent upgrade, I replaced a couple of older, smaller hard disks (one SATA, one parallel ATA) with a new 500 GB SATA disk. I retained another old PATA drive. So the new setup has one (new) SATA and one (old) PATA.

The BIOS of my Asus M2N-MX mobo is set to boot from the SATA drive. But, since this upgrade, I find that every time I install new software the boot order changes and the PC tries to boot from the PATA drive. Since this drive is not bootable, I get the "NTLDR is missing" message. I reset the BIOS boot order and everything is OK again until the next time I install new software - and this can be as little as the recent upgrade to Spybot, or Windows updates.

Any suggestions as to how to fix this?

[btcomm]

Thats a tough one, only thing I would suggest it that you do a bios update if one is available for your motherboard.

[SuperSparks]

If the CMOS is not remembering the setting, change the motherboard battery.

[mhl]

Nick

The CMOS battery is more or less brand new. CMOS remembers the settings just fine until I add software, then it changes. I can make changes to the BIOS settings and these are retained OK. When I install software, the deliberate changes which I have made (e.g. date/time) are retained but the boot order changes - there definitely appears to be a causal relationship.

[SuperSparks]

That really is a weird one, it's the first time I've ever heard of anything like that

If it were me I think I'd try Btcomm's suggestion and reflash the BIOS.

[Train]

Asus
Had trouble with them in the past for doing that if the bios seen a bad shutdown. A7V series mobos.

The BIOS upgrade may take care of, notice the MAY bit please, just do not push the shutdown and let it take its own sweet time.

[mhl]

Well, I've flashed the BIOS to the latest version. And on re-booting .... yes, you've guessed .... the boot order has changed again!!!

Aaaaargh!!!!!