Am I entitled to keep the laptop given to me by the company instead of the salary I did not receive?

The computer must be returned to the company. It is not permissible to take it as compensation for unpaid salary, as the company is not responsible for the expenses of quarantine, and it paid them to deduct from the salary. Even if you have a right to the salary, you must complain to the competent authorities. It is not permissible to take the computer in lieu of your right, because the issue of seizing a right is restricted to the establishment of the right, the prevention of accessing it, and the inability to obtain it except through that specific means.