They are taking part in four days of gruelling tests which, says competitor Andy Richards, will tax brains as well as brawn.
"We understand there's a lot of lateral thinking involved. We will be set a series of 10 challenges none of which will be revealed until 15 minutes before we set off. Then we have to pick a team of four to represent us," he explained.
The Coleford team will be competing against over 100 other teams from major British companies.
"It will basically involving getting from two points but with obstacles in between and we do not know what they are," said Andy.
The teams of seven have to include a company executive – in Coleford's case Mark Evans – and ages range from mid 20s up to 40.
In a fitness drive the local team – Allan Matthews, Andy Richards, Dave Treherne, Andrew Payne, Pat Delany and Mark Burton – have been canoeing on the Wye and strengthening muscles on the Motiva rope course at Christchurch.
"There's a real buzz about everyone and we are looking forward to the challenges," said Andy.
"To be honest I don't know even know what the prize is but we have done really well raising money for the charity NSPCC. We have already raised £3,000," he said.
The Microsoft Challenge is being televised and local people can follow the team's progress on http://www.challengerworld.com">www.challengerworld.com