Restore data after installing Ubuntu?

Since I was not satisfied with the performance of my laptop, I decided to install the latest version of Ubuntu next to Windows 10. Unfortunately, something went wrong with the installation and I was forced to format my hard drive and install Ubuntu. Is there a chance I can recover my old data?

I do not think you were actually forced. You would have had to cancel the installation right at the beginning, then the data would probably have been saved. Now it gets harder.

Open a command prompt in Ubuntu and type "sudo apt install testdisk" and then "testdisk". This may help you get some of the data back.

Yes, but it is low.

By partitioning, the partition table is gone and the subsequent reinstallation has also overwritten data. Testdisk has already been named as the first point of contact.

Important:

Data overwritten during the reinstallation of Ubuntu are irrecoverably lost. Only what has not been accidentally overwritten and only lost by partitioning can theoretically be restored.
That's why the system does not start anymore. Make a bitwise copy of the disk and work on it (with dd in the command line.) Careful! Dd can also very well destroy data).
If the data was important to you, hire a specialized data recovery company. Expect a 3-digit amount.

I was forced to format my hard drive and install Ubuntu. Is there a chance I can recover my old data?

Forget it and look at it as a lesson.

Of course, there's a tiny chance theoretically, but for a layman, this is a mammoth task.

Linux Hase