To run Ghosts you'll need to upgrade to a 64-bit version of Windows 7 64-bit or Windows 8 64-bit; in part the memory requirements are 6GB and exceed 4GB (32-bit limit). Unfortunately there is no 'easy' and automatic way to accomplish that task. You'll need to backup data and re-install all applications. For backup's in general it's a good idea to have an external storage drive.
Windows FAQ - 32-bit and 64-bit Windows: frequently asked questions
Activision minimum requirements see - Call of Duty®: Ghosts
Forum minimum requirements* see - http://community.callofduty.com/community/call_of_duty/english/ghosts/blog/2013/ 10/23/call-of-duty-ghosts-pc-system-requirements
* note variations
As Momba1 said, Microsoft does not provide the ability to upgrade a 32 bit version of Windows to 64 bit. You will have to do a "clean" install and re-install your programs/games. (*** of course backing up all your important documents, pictures, music first because you would lose them).
Running a 64bit version of Windows in a virtual machine as Pur4ido suggested will not work: the amount of ram (memory) the virtual machine would use would be limited by the Host OS. My recommendation: Buy the upgrade edition of Windows 8 off of Amazon for like $75.00 (for the Pro version, the regular is proabably cheaper). You can then get the upgrade to 8.1 for free. There are also free programs you can install to bring back a better "start button" and menu.
Now if you have the Retail (not OEM) version of Windows 7, your Windows 7 key (serial) should work with the 64 bit version of Windows so there would not be an upgrade cost.
can i play ghosts with:
Intel core i7-3632QM 2.2 GHZ with turbo up to 3.2GHZ
NVIDIA Geforce GT 630M with 2BG dedicatet VRAM
can i play with this???
ghosts must have:
OS: Windows 7 64-Bit / Windows 8 64-Bit
CPU: Intel® Core™ 2 Duo E8200 2.66 GHZ / AMD Phenom™ X3 8750 2.4 GHZ or better
RAM: 6 GB RAM
HDD : 40 GB HD space
Video: NVIDIA® GeForce™ GTS 450 / ATI® Radeon™ HD 5870 or better
Sound: DirectX compatible sound card
DirectX®: DirectX® 11
Internet: Broadband connection and service required for Multiplayer Connectivity. Internet connection required for activation.
CAN I PLAY??????????
Run yes, sort of anyway uber low FPS/low details/low resolution, the GT 630M is your Achilles heal and I have no idea of the FPS you'll get, and I'd forget any AA settings or HD resolution (1920x1080). Here's some benchmarks from BO2, so take-off (guessing) 10%~15%; see - Call of Duty Black Ops 2 Benchmarked - NotebookCheck.net Reviews
You'll have serious issues in Multiplayer; assuming you can get it to run. I generally recommend the 700 series 'M' for notebooks.