I have no cd drives in my pc, How can i get an installer?

Not sure about that, but is this a real old computer, or a modern one but just no drive? If you look on Craigslist (usa) you can many times find old free pc parts and free systems, and quite often you can pull working cd/dvd drives from them.
Over the years I have occassionally ended up with small piles of them from gathering used stuff. You can also place a wanted ad on craigslist but that's a low traffic forum so don't bank on responses there.
New ones can be had for $15 and maybe less. You'll want to get a DVD burner even if you don't plan to burn anything, just for future proofing. They're so cheap it doesn't cost anymore. Don't get just a player and don't get a cd drive because dvd drives are backward compatible.
Check Newegg, Amazon, Ebay, Tiger Direct, you can even call local shops and ask if they have any used ones for sale for a few bucks. Ebay might be your best bet to get something super cheap with free shipping.
On Newegg, sort by 'most reviews', and that will show you whatt is popular there.

You have to look for a ISO in google.

New pc's are doing away with cd drives.

I have no cd drives in my pc, How can i get an installer?
Do you have a license code? If not, you need to get the game with license code to play it online. It's around 5 bucks on Amazon and eBay. If you have a valid license code and want installer, PM me.

Yes i have license code and i did it buy it,I have Limited Collectors Editions. AIso how can I add it to steam or can't I?

You cant activate it on steam. There are also external DVD devices that you can connect via USB if you want buy one, but I think the best you can do is download it somewhere. You can also use another PC to make an image of your DVD disc and copy it to your PC using a USB flash drive for example and mount it via daemon tools or a similar software.
Also, I think you can share your DVD drive in another PC and access it from a different PC.

There are also external DVD devices that you can connect via USB if you want buy one, but I think the best you can do is download it somewhere.
There are retail ISOs around internet that can be mounted without an issue since the game has no physical DRM. Also there exists
another
way to install it online which I will let him know.

Fry's sells a external usb cd drive for like ten bucks.

Fry's sells a external usb cd drive for like ten bucks.
Nah, no need for that. There exists an online installer, anyone interested shall contact me.