You may find something useful to you in the thread at Timeouts/timers on Win32 system.

PodMaster reports and demonstrates that alarm does work on Win32 in 5.8.x, and indeed his demo code works for me also, but when I try using it in any of the classic ways, like inside an eval, it doesn't seem to do anything useful. I'm not sure what I'm doing wrong, but I'll try and work it out/

There are a coupe of other solutions in that thread.