A method for operating a keyboard-video-mouse switch, the KVM switch being coupled between a plurality of peripheral devices whereby at least one peripheral device is capable of sending signals containing hotkey data and a plurality of controlled computers, the method comprising: (a) determining whether a hotkey mode of the KVM switch is initiated; (b) if the determination in step (a) is affirmative, when the KVM switch receives a first signal from a specific one of the controlled computers, directly forwarding the first signal to a corresponding specific one of the plurality of peripheral devices (S12, S14); when, within a predetermined time interval after forwarding the first signal, the KVM switch receives a second signal in response, determining whether the second signal is from the specific peripheral device capable of sending signals containing hotkey data; if the determination in step is affirmative, determining whether the second signal contains predetermined data (S16, S18) which includes hotkey data that adversely affect functions and operations of the specific controlled computer; (d) if the determination in step is affirmative, replacing the predetermined data in the second signal with irrelevant data to generate a third signal, and transmitting the third signal to the specific controlled computer, wherein the irrelevant data corresponds to the specific controlled computer and has no effect on the specific controlled computer and the specific peripheral device is a human interface device, and wherein the irrelevant data is a negative acknowledgement signal; and (e) if the determination in step is negative, forwarding the second signal to the controlled computer without applying any signal processing to the second signal, wherein if the determination in step (a) is negative, the method further comprises: (b') when the KVM switch receives a first signal from the specific one of the controlled computers, directly forwarding the first signal to the specific peripheral device; and (c') when the KVM switch receives from the specific peripheral device the second signal in response, directly forwarding the second signal to the specific controlled computer. (a) determining whether a hotkey mode of the KVM switch is initiated; (b) if the determination in step (a) is affirmative, when the KVM switch receives a first signal from a specific one of the controlled computers, directly forwarding the first signal to a corresponding specific one of the plurality of peripheral devices (S12, S14); when, within a predetermined time interval after forwarding the first signal, the KVM switch receives a second signal in response, determining whether the second signal is from the specific peripheral device capable of sending signals containing hotkey data; if the determination in step is affirmative, determining whether the second signal contains predetermined data (S16, S18) which includes hotkey data that adversely affect functions and operations of the specific controlled computer; (d) if the determination in step is affirmative, replacing the predetermined data in the second signal with irrelevant data to generate a third signal, and transmitting the third signal to the specific controlled computer, wherein the irrelevant data corresponds to the specific controlled computer and has no effect on the specific controlled computer and the specific peripheral device is a human interface device, and wherein the irrelevant data is a negative acknowledgement signal; and (e) if the determination in step is negative, forwarding the second signal to the controlled computer without applying any signal processing to the second signal, (b') when the KVM switch receives a first signal from the specific one of the controlled computers, directly forwarding the first signal to the specific peripheral device; and (c') when the KVM switch receives from the specific peripheral device the second signal in response, directly forwarding the second signal to the specific controlled computer.