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Operating system not found after installing linux mint

I installed linux mint along side windows 10 on an old laptop from 2012 (i7-2670QM),

after installation,
removed mint flash drive -> enter -> laptop rebbot,
and getting Operating sytem not found

Is there anything I can do to fix this, or do I have to try to install something else like ubuntu, or windows 10 again.

UPDATE:
I’ve inserted my mint USB flash drive to my PC, and I see it has been split, into 2 disks, 1st is 5MB and has boot, and EFI folders, is this something that balenaEtcher has done, or the mint install ( and 2.85 GB unallocated I see in Disk Management )