The company, which suffered disruptive virus attacks last year, believes it can make significant savings by freeing its support staff from having to repair systems and cleanse the network when viruses strike.
Although Mitsubishi uses anti-virus software to protect its internal networks, the company suffered infections because staff were forgetting to update their anti-virus signatures on their laptops when working from home.
Viruses have slowed traffic on the company network and, in one severe case, prevented the company's business partners from accessing Mitsubishi's computer systems.
"In the worst incident, from a team of 50 staff, we had 12 or 13 notebooks that had to be rebuilt. That was two or three days for the service team, on top of our day-to-day work." said Mitsubishi's IT manager Dave Berwick.
The software, SecureEXE, supplied by Securewave, contains a "white-list" of approved executable files and blocks any software that has not been approved, including viruses and hacking tools.
IT staff are currently testing and configuring the software on machines running 40 different combinations of packages, before a roll-out later this year.
Mitsubishi also plans to use Securewave's SecureNT software to lock down peripherals on its desktop and laptop computers to prevent staff from transferring viruses on floppy discs, or leaving the building with sensitive commercial files.
"Anything like CD Roms or floppies and USB memory sticks will be controlled," said Berwick. "It will pay for itself by freeing up our support staff."
Neil Barrett, security consultant at Information Risk Management, said it was rare for companies to go as far as Mitsubishi in locking down their systems.
"It is a good idea. A lot of companies lock down systems by restricting what users can do, but this is the first example I have seen of a company that has gone quite this far to restrict memory discs and floppy drives," he said.