Very few people have the ability to build Lady Heather for Windoze from source... pretty much everybodyl uses the binary. Having people build from source is not an option (except on Linux, it's relatively painless and the tools are easily available and free, plus Linux users tend to know what they are doing). The QueryPerformanceCounter() functions are available on Windows back to Win98... it's just that the various hardware implementations of the TSC instruction have lots of warts and idiosyncrasies. The QueryPerformanceCounter() system call tries to mask and compensate for these, but often does not do a good job of it. In the worst case it reverts back to doing the same thing as GetTickCount(). ----------------- > Can't you take care of this in the build system?