Claiming the depreciation on pc and laptop.

You can claim depreciation for the last five years as a Prior Period Expenses. Rate of depreciation is 60%.

For the newly purchased asset also you can claim depreciation for the year ending 31st march 2014.In this case asset  used for less than 180 days, you are eligible to claim only 50% of allowable depreciation as per income tax act.

35000*60%*1/2=10500.

I'm not sure about this ,you can wait for others replies

For query 1 - Specify the A.Y. for which you forgot to claim dep., then I can able to direct you

For query 2 - Provision stated by Mouli is correct but calculation is incorrect.

Mouli has taken value of asset Rs. 30000/-, it should be 35000*60%*50% = Rs 10500/-

Hope you two are satisfied