Thanks, as I only have light smearing guess best to leave alone!

I did a quick websearch and found this


The only easy to use solvent we have found for Araldite ( an epoxy
resin ) is Dimethylformamide - soak overnight at ambient temperature
and then see if the epoxy has become slightly soft, if so keep soaking
until it eventually swells and breaks away. Epoxy is not affected by
most common solvents - such as acetone, methanol, chlorinated
hydrocarbons, and hydrocarbons - at ambient temperatures, and I doubt
electronic components would like the elevated temperatures where they
do affect epoxy.

Note that the DMF works by swelling and softening the epoxy, which
slowly loses its strength and flakes off. I have encountered some
epoxies that seemed to be more resistant, but after a couple of weeks
they were soft enough for careful scraping to remove the material.

** SAFETY WARNING **

Any chemical that munches into epoxy also does damage to humans under
the same conditions, so please read the Material Safety Data Sheet
that comes with the solvent. I use a fume cupboard and gloves when
washing the the DMF from components with ordinary tap water. A garden
hose outside would be a suitable alternative. The solvent can be
reused if carefully decanted from the epoxy flakes.

Bruce Hamilton SRGXBHH [at] grv_dsirgovt_nz


I suspect that unless your windows are glass the windows will dissolve and leave the epoxy behind first.

if on the other hand we are talking of glass windows use a paint scraper

http://www.wilko.com/preparation/wilko-glass-scraper/invt/0343652

an example of the kind I mean.