Dual boot system failed, ubuntu file system missing during hard disk data recovery I had a dual boot system with windows 10 and ubuntu 18. Recently the system failed, the motherboard probably got fried by lightning during a thunder storm and its not booting anymore, no fan, no lights, totally dead. So I salvaged the hard disk to recover the data from it. I plugged in the hard disk to a windows machine using a SATA to USB adapter, but I can only see the windows file system in it, neither the linux partition is showing nor the files are showing anywhere else. How can I recover the files I had in ubuntu, is there any other way to see hidden partitions? Should I try plugging it directly into the SATA port instead of using a SATA to USB adapter? I have to invest in a new machine to do this and if it still cant access that data that investment will not be very fruitful.

The Ubuntu partitions will be ext4, so you won't be able to see them on Windows. There is some software you can use to read ext4, but I have never found anything that worked satisfactorily. Your best chance is probably using a Linux live USB drive. Instructions for creating one with Ubuntu can be found here. Boot using the USB stick, and select the option to try Ubuntu without installing. Then you should be able to use Ubuntu's file manager/terminal to copy files from your old disk.