Hi
To diagnose please check here, and after make sure you use a network band your phone can detect.
In your hotspot configuration's panel, please note the network name (SSID) & network password. Please enter it by hand inside your phone, in case you are in a wifi's congestionned zone to detect your hotspot.
Make sure that registry key is not set to 1;
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WcmSvc\Tethering
RemoteStartupDisabled
If it's a computer member of a domain, make sure in the local group policy that this settings is not set;
Computer Configuration > Administrative Templates > Network > Network Connections
Prohibit use of Internet Connection Sharing on your DNS domain network