About 8 years ago we had some plastic-frame windows installed, and the
window guys weren't exactly generous with silicone they applied between
frame and outer walls. There are fine cracks between a number of the window
frames and silicone attached to the walls. Would it be possible to apply
new silicone over the old? Removing the old isn't something I would
attempt-- I've done it in the bathroom (between fixtures and wall, or at the
joint of wall and floor) and it went OK, but on the outside-- No. Any
suggestions? TIA.

MB wrote:
About 8 years ago we had some plastic-frame windows installed, and the
window guys weren't exactly generous with silicone they applied between
frame and outer walls. There are fine cracks between a number of the window
frames and silicone attached to the walls. Would it be possible to apply
new silicone over the old? Removing the old isn't something I would
attempt-- I've done it in the bathroom (between fixtures and wall, or at the
joint of wall and floor) and it went OK, but on the outside-- No. Any
suggestions? TIA.

No problem. Just clean down the old stuff well with a wet rag and allow
to dry fully before you apply the new stuff. Basically you are just
sealing out the rain and that is the only sensible way to go. You could
replace it all but totally over the top.