Hi adil and welcome to the Forum.
A couple of questions:
Are you dual-booting with Windows?
Which edition of ZorinOS are you running e.g. Pro, Core, Lite etc?
Can you edit your profile to indicate that there, as it will save that second question being asked again in future.
When you installed ZorinOS did you turn off (UEFI) Secure Boot and Windows Fast Startup. See this thread Before you install