If your home has timber windows, then it is important to maintain them properly, in fact any timber on the exterior of your home will need attention if it is to continue to carry out the purpose for its installation.
It is easy to see where and when this work is required when small flakes start to appear to the surface of the paint, this means that over time a combination of the elements, heat, cold and moisture have taken their toll.
Once the paint starts to fail it will be a relatively quick process for the surface to worsen, especially as winter approaches you have been unable to refurbish the affected areas. The small cracks or blisters allow moisture to get in behind the paintwork, then as soon as the temperature drops to below freezing the moisture expands and causes the paint crack a blister even more, which eventually results in hardly any paint left at all.
When this has happened it is important that you go about the refurbishment in the right way. Using a scrapper remove any loose paintwork, you may at this point notice that the timber itself has changed to a dark colour, or even rotten. If you do have rot then this must be cut out and removed completely or it will just come back to haunt you, but make sure you get it all.
You may need to replace a full piece if it is that bad and if this is the case you want to contact a joiner as this can be tricky for a DIY fix. If the surface is not that bad but is wet or damp to the touch, it is really important to ensure this dries out fully before you attempt to apply any new paint.