For Windows PCs which request the DNS servers from the DHCP server, you could set the DHCP server to return only the DNS server you want the PCs to use (your own DNS server IP). This should work whether it's a separate DHCP server, or your router with DHCP builtin.
Unfortunately this will not change any PCs which have hard coded DNS server IPs.
I need a way to set spacific DNS servers using like a exe installer.
The reason is we have people working from mobile computers and we cant control all the routers, i mean here in office, we use "Obtain DNS Auto" but for the mobile computers we cant use that, so I need a way to change them usign like an EXE / Regedit.