Hello KarannSiwal, If we install the operating system with Dell OEM version (Operating system disk shipped with the computer), the product key is not required. For the operating system with the retail version, the key will be available on the disk.I would like to know if you have got the operating system disks for reinstallation of operating system. You may also locate the Windows 7 Product key on the bar-coded sticker as shown in the image below: [IMAGE]  Please reply if you have any further questions.
i have lost my window7 key of my desktop dell inspiron 545s, so kindly send me the same.
lost window7 key for dell inspiron desktop 545s