which one is very safe ( high secured) linux or windows ..?
both systems can be hacked if you use them unwisely. If you click on a spam link or install a javascript in your browser, it doesnt matter if you have linux or windows or osx (mac). Historically Mac's has been the most secure operating systems but to be true secure use a cold storage wallet like Nano Ledger or create a paper wallet.
Cryptocurrency is like real money, if you loose it, its very hard to claim it back.
Several things can theoretically happen
1) A keylogger can be installed and read all your keypresses
2) A javascript can be launched, which might steal your login credentials
3) A malicious software can be ran in background and wait for you to send cryptocurrency, it will try to change the receiver address
4) You can initiate a ransomware virus which will encrypt your drive and extort money from you
SO, just dont click on any link you have no idea where its from (even on telegram)
/KX