Simple steps to troubleshoot network on Windows machine

Few days ago I faced one interesting problem - client was able to enter all sites besides one. Below I list all steps used to identify the source of the problem:

1. verify settings on the NIC (Network Interface Card):
   ipconfig /all | findstr /ic:"adapter" /ic:"ip address" /ic:"mask" /ic:"gateway"
2. verify IP routes, especially route to the needed site:
   route print
3. verify DNS response and check if resolved IP addresses in the both outputs are the same (it's needed because site's IP address can be in C:\WINDOWS\system32\drivers\etc\hosts and windows uses DNS server when executing `nslookup` and `hosts-file` when ping is executed):
1. nslookup google.com
2. ping google.com
4. Verify connection from cmd (If connection is successful output will be like:
   Trying 62.212.252.119...
   Connected to google.com.
   Escape character is '^]'.)
1. telnet google.com 80
2. telnet google.com 443
5. ping needed site. If error occurred, lower packet size until ping returns normal answer:
   ping google.com -l 1500

In my case problem was in MTU size in the router at the customer side.