My windows is not genuine

How did you restore your Windows to your system after you reformatted the hard drive? If you did it from the recovery CD/DVD provided from Sony then either on the disk or it's packaging, or within the documentation kit with the system when you bought it you should find the activation code. If you can't find it contact Sony with your systems serial number they should be willing to sell you a new recovery disk with the needed code.

If you got this system used or the dealer who sold you the system failed to supply you with the documentation kit you may want to talk with them as well. You may end up needing to buy a full copy of Windows to fix this.

If you restored your files from a back up then you need to enter in the activation code within the System control panel to activate your Windows OS as being genuine.

If your company supplied your system to you they may have a corporate license and depending on which Windows you have it may require you to connect to their network to validate the license. Talk with your IT people to see what steps are needed to fix your system if you can't connect and/or need the apply the corporate license activation code for your system.

You don't need to reformat your drive to fix this, only find and apply the correct activation code for your copy of the Windows OS. If you put a different version (newer) on then you'll just copy over your current install.