I need help (if it's even possible) to have a running count of total items
that meet a certain criteria within the same row (for the entire worksheet).
For example:

A B
C D
1 Item Area Summary Area 1
2 Panasonic 1
3 Toshiba 2 Laptop Issues
2
4 Panasonic 1 Scanner Issues
1
5 Scanner 4

I need to know the formula to put into cell D3 to have it auto-count a total
based on the same row values from columns A and B. Based on that formula I'm
hoping to figure out the other items I need to do this for.

Thanks in advance for any help you can provide...!