Remove paint and grime from aluminum windows?
If you just want to give them a light cleaning you can use a few pads of 0000 steel wool pads and a little elbow grease then spray with clean water.  If you have aluminum discoloration or mineral deposits you may want to use a chemical such as Aluma-Kleen (which is bio-degradable) or a even a homemade recipe my grandmother use to use was 1 part water to one part vinegar (acid) to clean aluminum. Always rinse with lots of clean water and wipe down dry to prevent further minerals from staining.  Hope this helped.