Stuck in PXE Boot screen and no operating system found and pc don't want to boot in bios?

I have the Lenovo thinkpad egde e320

TYPE 1298-A6G S / N LR-6CEP3 12/01

PRODUCT ID: 1298A6G

So, i switched in the bios settings the boot mode from "both" to "only legacy" and from then my pc boots only network (PXE) but it can't logically and it shows me "no operating system found"

And i tried everything to get in the bios again to change it back, but it didn't work.

At the start, it says at the corner of the screen that the bios settings were loading, but then the next display is network booting (PXE).

And yes, "both" as boot mode in the bios is working fine, but i can't get in the bios to change it back. Please help 🙏

Ps. Preparing boot device list is also shown but still boots in the PXE mode and so on.

I think your chances to get a reply are higher on an English-speaking platform rather than a German-speaking one.

Nevertheless, is a hard drive installed with some bootable OS? Or are you trying to boot from a USB drive?

Haha sorry, I can also write in German…

Win10 is installed I just switched from "both" to "only legacy" in the bios and since then the PC only starts in the PXE mode = no operating system found. The problem is, I just can't go to the bios or the device manager list. Although it always says at the bottom left that it is in bios or in devices. Loads, it still boots into PXE mode…

Ps. "Both" worked without problems.