Grub error "attempt to read or write outside of disk hd0"

[Morgonte]

I try to run a dual boot: Ubuntu Studio 19.4 and Win 7. The computer has 4 hd:s, Ubuntu Studio on sda2 and Windows on sdd1. Sda1 used to hold some data for the windows system but I erased it to make sda a linux/ext4 only drive.

However, when I try to boot Ubuntu Studio from GRUB I get the error "attempt to read or write outside of disk hd0". I've tried Boot-Repair, but so far with the only result is that my windows boot has been messed up. The grub error persists. However, if I boot sda2 from UEFI:s boot menu It works just fine.

Here's the data from Boot-Repair:

http://http://paste.ubuntu.com/p/RF84WTpcRn/

How can I get Grub to work properly?

[oldfred]

Working link, is this yours?
https://paste.ubuntu.com/p/RF84WTpcRn/

With multiple drives & installs, only use Boot-Repair's advanced mode. You typically do not want one grub installed to all drives which is its default fix. In advanced mode you select install & drive to install boot loader into.

Install Windows boot loader to MBR of sdd. Boot-Repair may work and installs a Windows type boot loader, syslinux. But often better to use your Windows repair/recovery flash drive to run fixMBR command. Fixes will not work unless sdd1 has boot flag, so make sure you have a boot flag on that partition. You can use gparted or your Windows repair flash drive and set active.

Grub only boots working Windows.
So if newer Windows 8 or 10, it may turn fast start up back on and then you have to directly boot by choosing it in BIOS. Also if it gets corrupted & needs chkdsk grub will not boot Windows. So always keep Windows boot loader in MBR of Windows drive.

It also looks like you have a 2.7 TB drive, but partitioned with MBR(msdos). MBR has a hard limit of 2TB, so you converted your 2.7 drive to 2TB. MBR was designed back in the 1980's when GB was very large and TB unheard of.

GPT info
https://support.microsoft.com/en-us/help/302873/frequently-asked-questions-about-the-guid-partitioning-table-disk-arch
http://www.cyberciti.biz/tips/fdisk-unable-to-create-partition-greater-2tb.html
http://www.ibm.com/developerworks/linux/library/l-gpt/
http://www.rodsbooks.com/gdisk/whatsgpt.html

Converting to or from GPT - must have good backups.
http://www.rodsbooks.com/gdisk/mbr2gpt.html

[Morgonte]

Thanks oldfred, for providing good suggestions. However, Whatever I tried, I couldn't get rid of the "outside of hd0"-error, neither can I get Win7 to boot... Finally I decided to get rid of ubuntu studio and install the latest linux mint. Mint seemes to work, but I do not get back windows, yet.

but since I no longer have any *buntu flavour on my system, I guess my question is Off Topic now. I will have to seek advice somewhere else. Still, thaks a lot!