I have been seeing a situation while performing a vulnerability scan on one of the Windows server. I tried to perform the Vulnerability Scan using Standard scan (1900 TCP Ports and 180 UDP ports) but scan did not finish even in 2 hours 30 minutes. So I had to cancel the scan. After that I tried to run a new scan using light scan option (160 TCP Ports and 30 UDP Ports) which finished in approximately in 16 minutes.
Now I don't understand this behaviour. If anyone of you have any idea, please let me know.