Inside window leak

[Hotfudgemonday]

I have a leak in one of my windows where the water is coming in dripping down the one corner at the bottom of the window. It has caused visible damage to the trim around the window and the plaster in the wall below the window.

I checked the weep holes and they are clean and clear. On a dry day I decided to check and make sure that the windows were draining properly by pouring water into the window. The water drained out the weeps holes fine but then pooled on the sill. Since it didn't run off the edge the only place for the water to go was back into the window. This is when I noticed the window frame on the inside was starting to drip water.

Does anyone know what is causing this and how to fix it?

[pushkins]

Is this window a vinyl replacement window ?
There should be a bead of caulk where the window meets the window sill.
If these are vinyl windows then there should be a bead of caulk all the way around the exterior where the window meets the sill and stops.

[Hotfudgemonday]

They are vinyl windows, not sure if they are the originals for the house but anyhow, I had checked the first time I was trying to figure out the problem and was pretty sure there was caulking around the outer part of the window. I decided to double check it though and they had put caulking around the window except for right underneath the weeping holes. So the water would go out the weeping holes and then leak back into the window underneath the holes.

I've put caulking to seal it up and see if that is what the problem is. Once it's cured some I'll test it and, hopefully, if that is the problem, I'll go about removing the old stuff and putting in new caulking properly.

Thanks for the suggestions, I doubt the light would have come on for me otherwise.