Despite being one Formula One's most famous names thanks to nine contructors' championships and drivers' titles for the likes of Nigel Mansell and Damon Hill, the Grove-based team have slipped into decline in recent years.
Without a win since 2004, Williams currently stand on the brink of their worst season in the sport for more than a quarter of a century, with drivers Rubens Barrichello and Pastor Maldonado having scored just five points between them.
Even then that has to be put into context, given that the top 10 are now allowed to score points. During Williams' early days in the 1970s, when the team were trying to find their feet and they were at their previous lowest ebb, the two ninth-place finishes from Barrichello and Maldonado's 10th would not have counted.
These are wretched times for the team founded by Sir Frank Williams and Patrick Head. Yet from next season Williams will be powered by Renault engines, returning to their famous partnership from 1989 to 1997 when they dominated the sport.
Given that Renault have helped propel Red Bull to world title glory over the last two years, Ghosn, chairman and CEO of the Renault-Nissan alliance, has no doubts they can also help Williams.
"We trust the Williams team, and obviously we supply engines to them because we think they have much greater potential than what they are delivering today," said Ghosn.
"They have the strategy, they share it with us, and we think by supplying them with engines it will help them re-position themselves in a much better place in Formula One."
Ghosn is also adamant that, for now, Renault will remain an engine supplier rather than a constructor. Although an F1 team currently bears its name, the French manufacturer sold its stake after the infamous 'crashgate' saga at the 2008 Singapore Grand Prix and the outfit now carries Lotus branding.
Even so, Ghosn conceded that you can never say never. He added: "Every CEO is going to tell you 'that's it, this is forever', but that's not the case.
"We change, we adapt with regard to circumstances, technology, the competition.
"But for the moment and for the foreseeable future, we feel very comfortable with how we are, so you can count on this for the next three to five years."
Williams will be the fourth team on the grid to be powered by Renault and Ghosn said they would be happy to supply more if FIA rules allowed.
"We have the team of engineers, technology and the plant, although obviously we have to prepare for it," he added.
"We're ready to respond to the needs of any team who would love to have a Renault engine."