microsecond on vb software

hi
I am beginner level programmer on vb.Please help me
I want to find microsecond in vb software. How can I find it.
I know time$ command but this command don't give me microsecond .it gave me hour , min, second together with timer function gave me milisecond. if you have any info about this subject please send me very urgent. I want to controller with paralel port and I need 900 microsecond pulse.
Thanks
Regards
Your friends. if you accept.

you cannot achieve microsecond resolution on wintel machines. The VERY best you can do is 1000 microseconds (1 millisecond) and that is not reliable at all. Only the 55-millisecond clock is reliable, and that does you not good at all for the kind of resolution you want.