[SharphSonirak]

I don't know where to start.

First, Linux servers are much, much cheaper and give equal and sometimes even better performance. You don't need 8 GB RAM and 4 CPUs for a CS 1.6 server - half of that performance would be more than sufficient. I used to run CS 1.6 surf server with 20 slots on OVH VPS with Ubuntu:

OpenStack KVM
1 vCore
2.4 GHz
2 GB RAM
10 GB SSD
€2.99 /month
Price is extremely important if you plan to keep your server in long term.

Secondly, you need Steam Pipe (former HLDS tool) in order to run CS 1.6 server. And after that, you install dProto module so non-Steam players can get in.

Overall, you need a lot of technical skills if you want to build and maintain a server from scratch. My suggestion is that you should ask for a refund, and then start a server with some already established companies like gameservers.com, who provide technical support and give you an option to install various mods with 1 click.

But from my personal experience - I don't think it's really worthy at this point to run a CS 1.6 server. Majority of players are 3rd worlders who cannot afford a better computer to run CS:GO. They only make trouble with their cheats, high ping and racist language. All good players moved to CS:GO. When I compare 2007 and 2017, it's like day and night. The best days of 1.6 are over and it will just keep getting worse and worse in years to come.