JK It is also likely that the new widows have 'tightened up' your house and are not allowing warm moist air to escape as it once did. I had a similar problem. When we moved into our drafty house 6 years ago, window condensation was not a problem. But with the replacement of our gas furnace that now uses outside air for combustion; replacing our water heater from gas to electric (again, inside air not used for combustion and them expelled to the outside), installing storm windows throughout and new exterior doors with modern weatherstripping....this all served to dramatically reduce the inflow/outflow of air for our house. Then, with natural moisture producing activities (showers, kitchen, breathing, etc), the moisture content in our house went way up, leading to window condensation we had not previously experienced.
If this is your case, I don't think there is an easy answer. Dehumidifiers is one possibility, as is an air exchange system that periodically expels inside air through a system that extracts much of its heat and transfers this heat (but not the humidity) to incoming fresh air....although you typically only find this kind of system in new construction.