Cook (pictured right) took interim charge following the departure of Mark Collier in mid-January.
The Bluebirds have moved up seven positions in the Vanarama National League South table since the changeover, currently sitting in twelfth-place.
The Wiltshire outfit have picked up five wins in the ten League matches under Cook, including victory against play-off chasers Maidstone United and Hemel Hempstead Town.
On the appointment, Chairman Neil Blackmore (pictured left) said: "Mike has achieved a very noticeable improvement in team performance since his time in temporary charge.
"The Board of Directors and I were unanimous he should be offered the appointment as permanent First Team Manager and that now was the time to do so. I am delighted he has accepted the position.
"The marked difference in recent team performances is undoubtedly due to his approach and previous experience and I look forward to working with Mike as we endeavour to take the Club forward both on and off the pitch.
"I am confident that Mike and his team, whom he brings with him, will continue to build on the excellent start he has made at the Club and the CFTC Board will do what it can to support him in that aim."