Power up and down problems

[ermc2]

I have two systems running Windows 98. One has a problem shutting down. Recently, after no known change, trying to shut down results in a restart, every time. Displays the "windows shutting down" messgae, but then goes to the bios screen and restarts. I have to hit the power off button during the bios startup. This system also has begun to startup and shutdown very slowly, like, lots of things are going on.
Does reinstalling windows without formatting cause loss of data and programs, or just reloads the windows operating system?

The other system I inherited from a "computer wizard". Right. Anyway, I found that the only way to start it is to power it up three times. After the third power-up and down sequence, a blue screen message says something like - "you've exceeded the number of times you can try ..... Starting in regular mode", and it starts windows normally. It's an old system and I think the wizard fiddled with it before he gave it away. I can't contact him any more.
Anyone have any ideas?

 

[Addis]

I don't think Windows 98 has a repair install feature. In XP you can do a repair install which will retain most programs and save data, however in 98 its not possible. Without formatting data should be retained but I'd just make sure by putting it into a separate folder incase its overwritten.