This laptop is decade old and I want to make it work .But it's constantly restarting and couldn't find any help on internet.
In the bios there is no option for formatting or repairing. Any advice could be helpful and apperciated
Well u asking so apparently can't on your own, which is going to be a problem because all we can do here is give u general directions, the rest is up to you.
So can't find Internet info tells me this is a no-brand laptop. Bummer, and I assume you don't have any original documentation or discs? Bummer+. If a recovery partition exists, one would get there via some hotkey combo during boot but wo ANY documentation, who knows.
Attempt to install new OS via bootable USB?
Old laptop you have to assume battery dead, may wanna attempt boot with battery removed.
BIOS do not provide for formatting or restoring. It's function of the recovery features which are invoked with "secret" key combination unique for each laptop brand.
Decade old means it's from C2D days, probably maxes out at 2GB RAM. It most probably came with Windows XP. It might boot with USB key, or might boot from CD only. While you can use this for some everyday work, it will be generally slow, and XP is way too old for modern times.
The best you can do - find out the specs, and post them here. Windows 10 could work if there are generic drivers available (and for some components there aren't). Linux is another option as well.