League Two strugglers Northampton Town have named Aidy Boothroyd as their new manager on a one-year rolling contract.
The Cobblers are currently three points above the relegation zone.
"It's a big challenge but if it was easy anybody could do it. I'm excited about this challenge," Boothroyd told BBC Look East.
"I feel I'm a much better manager than I was six years ago.
"I'll certainly be using some of the things I have used with other teams that have worked. And I'll be thinking about things that haven't worked so well."
Chairman David Cardoza added: "From our talks it is clear that Aidy knows the problems we have been suffering and he has done his homework on us.
"He is a good age, he already has plenty of experience from managing in the Premier League and Football League.
"He knows the challenge ahead of him and he has the hunger and the desire to succeed and follow up the phenomenal success he has already had in his career as a manager.
"We took on board lots of advice and plenty of opinions from people within the game and the message came back loud and clear that Aidy was the best candidate for the job.
"We were looking for a special type of manager who can succeed in two equally important tasks. We need someone who can work to steer us away from the position we find ourselves in in the short term, and someone who can take the club forward in the longer term."
Boothroyd has been out of work since March when he was sacked by Coventry after less than a year in the job. He left the club following a run of 16 league games with just one victory.
The former Norwich City youth coach switched to the Ricoh Arena from Colchester United, whom he led to eighth place in League One in 2010, their highest finish since they were relegated from the Championship four seasons ago.
His greatest success was achieved in his first managerial role at Watford when he guided them to the Premier League via the Championship play-offs in 2006.
He takes over a side that have not won in their last nine outings.
Since Johnson's departure, Town have lost their two games and 4-1 under two different caretaker managers.
Johnson's assistant David Lee was initially placed in temporary charge, but he was quickly replaced by goalkeeper coach Tim Flowers.
And Johnson's brother Peter has left his role as scout at the club.