This article will explain you how to get your product key and serial number of i don't have a cd and the product key for windows on my notebook's label sticker cannot be read anymore.
Actually you can not contact your system manufacturer and request assistance from them as from what I know no manufacturer records which Key went on to which system and you're out of luck in this case.
However, If you use the manufacturer's recovery system, or the Recovery Disks, you should not need your COA Key (the one on the sticker).
Your best option if you want to reinstall is to acquire the appropriate Recovery Disks - either direct from the manufacturer, through a reputable supplier of such things, or by creating them yourself - read the manual of your system for instructions.
But the question now Is that really a guarantee that if I will be using the recovery disks then there will be no use of the COA key anymore. If you are using a DELL PC, then its sure it wont ask for a serial number if you are installing the same machine. But as far as HP and other brands they do ask some times. Its risky to start installing or formatting the system without having the correct product key.
Seeing that you paid a lot of money for your software, it would be a good idea to keep a printed record of all your license numbers, when you bought them, where you bought them from and how much you paid.
There can be one possible solution to this problem.
You can use some third party software to know the product key of all the software's that were installed in your Windows Operating System. The one that I use and I can recommend is Product Key Explorer. But you need to purchase the full version to get the product key of the software's installed. If you are really serious on getting back your product and serial numbers, you can use this software. Follow the link before or you can Google for this.