More than 150,000 home computer users are helping scientists to find new ways to treat diseases like Alzheimer's.
The scientists use spare capacity in home computers
They are signed up to Folding@Home, a global network of computer users.
Scientists use spare capacity in these computers to test algorithms designed to show how potential drugs will bind to proteins in the body.
Many diseases are caused by protein malfunctions. Scientists say the project is starting to reveal what type of drugs could fight these diseases.
Folding@Home was set up four years ago by scientists at Stanford University in the US.
Users download a programme, which enables scientists to use spare capacity in their computer to test their algorithm.
Speaking at the American Chemical Society's national meeting in Philadelphia, Dr Vijay Pande of Stanford University said the project could help to find new drugs for a wide range of diseases.
The programme is designed to show how certain molecules, the key ingredients of any drug, will affect specific proteins.
In the past, computer-based algorithms have not proved accurate enough. But Dr Pande says his programme gets around that problem.
"For almost 20 years, people have been talking about doing drug design computationally but the real challenge has been getting sufficient accuracy," he said.
"Our main goal was to come up with methods to really push that accuracy to the point at which our methods are pharmaceutically useful."
Dr Pande says computers can be used to simulate work that would take many years to complete in the laboratory.
"We can do the hard work. We can study the things that would be hard to investigate just synthetically and then make suggestions for which ones should be followed up.
"I think it may open the door to a new range of therapeutics that we just can't access very readily right now."
Dr Pande said the results are promising. "I think we're at the point where pharmaceutical companies start to get interested."
Researchers at Oxford University set up a similar project to try to find new treatments for cancer.
The Screensaver Lifesaver project now harnesses the power of 2.8m computers around the world.
Professor Graham Richards, who set up the project, said such schemes are playing a major role in drug research.
"We now have 2.8m PCs signed up so we actually have more computer power for this type of work than all of the pharmaceutical industry put together," he told BBC News Online.
"We can do things that the major pharmaceutical companies cannot do."
The Screensaver Lifesaver project recently completed research into potential treatments for anthrax and smallpox. The results have been passed to the US government.
It also identified 14 potential targets for fighting cancer. The computers are now being used to try to hone in on these targets and identify those most suited to being turned into drug treatments.
"We are trying to narrow those results down. It costs money to make and test these drugs," said Professor Richards.