ddk timer interrupt clock windows
As uther8472 said, for creating a timer there is no need to hook the timer of the PC
(and in all case it's not possible, the timer is used by windows for the multi-tasking. To do what you want whit the timer, you should unlock port range of the timer, and after, all you do with the timer will be repercuted to win - accelrate the timer accelerate all things that are related to time, for example cursor blinking, effects on windows and so on ... very dangerous -- it DO NOT said it make windows go faster !)
To use timer you can use
-SetTimer, not very accurate (more than 10 ms)
-Multimedia Timer (you can expect 1 ms)
-Timer in a driver. You can increase the rezsolution (not really easy), but it can be made.
Another mean to do precise timer is (if you have a Pentium - it don't work under 486 and so on .. but today ...), is to use the time stamp of the processor (a counter that count at the frequencey of the processor)
Another time, it should be done in a driver ... but this I have already made it (PM me)
The first question was 'how to hook an interrupt'. Under Win9x, you should use the things provided with the DDK. It's not very esay, but it's possible ...
Un der WinNT/2K/XP you should use what is provided by win too .... but you should handle PNP and so on .... not very esay ...
Other possibility under NT/2K/XP. Hook directly the interrupt. it's not as simple as in real mode (the processor is here in protected mode), BUT it's possible, and work well if you don't do bad things in it (andf this is not so easy), but I do it with succes ...