I need instructions on setting the alarm for the Pulsar Chronograph 100M. I'm able to set everything else. Your response is greatly appreciated. THANKS!!

I answered this for different Fossil watch post, but I believe it will be the same for your watch.
I'll re-post the answer below.
------

To set the alarm on these models of Pulsar watches, do the following:
Looking at the face of the watch, there are two buttons and a crown on the right side. The TOP button is Button "A". - The BOTTOM button is Button "B".
There are 3 positions on the crown: IN (#0), FIRST CLICK (#1) & SECOND CLICK (#2). 
The small dials located at the bottom of the watch face (6 O'clock) are the alarm minute and hour dials.

First, pull the crown out to the second 'click' (position #2) ... This is all the way out. (STOP THERE! Pulling harder will harm your watch! Don't try to pull past position #2!)
Second, set the correct time. (plus one or two minutes... time to complete this.)
Third, with the crown still out to position #2, push button "B" (bottom) until the alarm minute and hour hands are set to the present time (same as the large dials).
Fourth, push the crown all the way in- to position #0.
The current time on the large dial should read the same as the small alarm 'time'. {This is the CURRENT TIME, not the alarm SOUND SET.}
To set the alarm SOUND time, pull the crown out to the first click (position #1).
Push button "B" until the dials of the alarm are at the time you want the alarm to sound... It can only be set within 12 hours! ... It does NOT know "am or pm".
When the desired time is set for the "alarm sound", push the crown all the way in (position #0).
The alarm dials will now indicate the time for your alarm to sound, NOT the current time. (this way, you know that the alarm is engaged.)
To reset the alarm- or disable it, pull the crown out to the first click (position #1) and hold button "B" down until the dials advance and stop at the current time... it will stop at the current time- then release button "B". --- Push the crown back in (position #0) and the alarm will now be disabled.

If the alarm dials are always moving and at the current time, you know that the alarm is disabled.
If the alarm dials are stationary and not moving with the time, you know that the alarm is engaged and set to the time shown.

I hope this helps.