Turned on computer this morning (Dell T5810, legacy BIOS, W10, )... won't boot and displayed "invalid partition table". Normally that's a problem on the drive (MBR?), but I swapped drives from other computer and got the same message. The problem is not with the drives themselves, but coming from elsewhere. Any ideas? Tks.
No, booting from same source as yesterday (SATA III). Didn't expect it to work, but tried changing SATA from AHCI to RAID. Didn't work. Thought maybe the setup had switched by itself from "Legacy BIOS" To "UEFI" and was therefore looking for GPT partition.... but not. In an area with high static electricity... that could be the problem, but it could also be "anything". CMOS battery tests OK.
Boot order and UEFI settings in the BIOS oviously matter, sounds like you went through that though. So... Kick yourself for not having a legit DR plan in place. And I mean kick yourself hard, directly in the balls if possible. You should be able to restore a full system disk image via CD, USB, or PXE inside 30 minutes tops. You are taking complete backups, right? But, it sounds like you're behind the 8ball because your backups consist of a pile of old floppy disks. The next best thing IMHO is to boot a so-called "rescue cd/usb" and flail around the internet asking questions on stupid forums. Lol, good luck.
Here's a useless message for you. I had this same problem(from what it sounds like at least) quite a few years ago. After a couple of days of trying everything I could think of and find on the internet I ended up going to a local shop and they had everything back up and running by the end of the day. The part that makes my post totally useless for you is at the time I didn't think to ask what they did to get it all up and running or I might have a possible useful answer. Sorry and good luck, maybe if you can find a local shop in your area you could get it back running. Geek Squad didn't exist back then and I am pretty sure they are real hit and miss finding one that actually knows more than how to set up a computer.
You're in too big of a hurry to be critical. I've got clone and image backups "up the wazoo". I posted, "the drives are not at fault".... so it has to be something else.
I'm critical because your DR plan sucks donkey cock. The fact you're having difficulty is proof enough... don't cry to me about it or try to defend it. Man up and admit it needs improvement; even if that means having a spare barebones machine around to confirm the disks are ok. If you really had good clone and image backups you'd be done by now. It absolutely is something else... your human error. You're overlooking something... either the disks are fubar, the bios/UEFI settings are out of wack, or some component of your machine (other than disks) is busted; eg controller, cabling, mobo. There's literally nothing in between. You're asking hit/miss questions on some random forum... this isn't the time to reject tough love. We're pulling for ya!
I had a similar issue last year. Win 10 system, I swapped SSD's and got the same message. What worked for me was updating BIOS.