Instant On - Wired

Hi

i have configured the switch with IP address 172.20.100.10, i can access it smothly,  the Management Vlan ID was 1.

after i changed the Management Vlan ID to 100, i cant access the switch now, how can i access the switch? and what is the IP that i have to configure my laptop with?

I have exactly the same issue, once the vlan is changed you cannot access the switch, its a factory reset for me 

Before doing something like this, the bare minimum you must do is set at least one port on your switch to VLAN 100 (untagged / access).  If you don't have any ports in that VLAN, then you can't manage the switch any longer and as Paul said, you must factory reset the switch to regain access.  

There are several other ways you could accomplish this depending on your goals, but choose the simplest way first.  Reserve at least 1 port on your switch purely for managing the switch in the management VLAN.  You never want to be in a situation where you can manage the switch, but only from another switch somewhere else in your network.