Are there true ulimit for windows? I'm finding ways/programs how to prevent one program eating 100% cpu.
windows system resource manager is the tool to set cpu limits per process, and adds process accounting interfaces. In older versions of windows this was what was on the second disk that no-one ever installed. In 2008 its a feature to be enabled. Its generally not as important on a windows system (from a resource control perspective) than a unix one as "nice" is built into the OS and process priority (with certain exceptions) can be changed on the fly in the gui, in addition under windows vist and above disk IO can also be prioritized (by default this is based off of the priority of the process). There is an API that lets you set disk IO priority explicitly but I am unaware of any utility to let you directly change just disk IO priority
You could use something like Windows System Resource Manager which has similar features to ulimit in that you can set CPU or memory limits on a process, user or session. This was available on Windows 2003 Enterprise and later.
A third-party option would be FasterWin which is strictly for setting CPU quotas on processes.
One solution would be to right click the process in
Task Manager and change the priority.