Perhaps as much as 20 years ago I was reading a sci fi book that I never finished and have wanted to pick up again but I can't find it. The memory of it continues to drive me mad so please help!! 
The story was based around the human race being controlled on multiple planets by a computer/AI that had been built by humans and had effectively taken over. The story followed some humans who tried to turn the computer off by travelling in space and learning more. The computer was programmed in such a way that there had to be the possibility of it being turned off. The computer had robot "agents" that I believe were called "vals". To get information from the various planets the humans could undergo a one time transmutation to another form of humanoid to meet the environment of the planet they were visiting. As I recall the story started off, or very early in the story, with a group of humans flying up to an abandoned space ship in orbit in a scout ship of some description. The controller of the scout was removed and put into the spaces ship (again, back to this possibility of shutting down the computer stuff). I can remember the controller saying "I'm ... huge!" and needing time to process what was going on as it had just gone from being a small scout to a massive starship. That's about all I can remember at the moment, please help if you can, this is a real head-banging-against-the-wall thing for me!! Thanks!
The story was based around the human race being controlled on multiple planets by a computer/AI that had been built by humans and had effectively taken over. The story followed some humans who tried to turn the computer off by travelling in space and learning more. The computer was programmed in such a way that there had to be the possibility of it being turned off. The computer had robot "agents" that I believe were called "vals". To get information from the various planets the humans could undergo a one time transmutation to another form of humanoid to meet the environment of the planet they were visiting. As I recall the story started off, or very early in the story, with a group of humans flying up to an abandoned space ship in orbit in a scout ship of some description. The controller of the scout was removed and put into the spaces ship (again, back to this possibility of shutting down the computer stuff). I can remember the controller saying "I'm ... huge!" and needing time to process what was going on as it had just gone from being a small scout to a massive starship. That's about all I can remember at the moment, please help if you can, this is a real head-banging-against-the-wall thing for me!! Thanks!
