We just bought a new home which is about 16 years old. It seems when the previous owner got ill, the house went into a bit of neglect and left unattended for some time. During that time I assume the windows were left open as almost every single one of the window bases (the slanted part that the window comes to rest on when closed) is rotted in at least one place. Sometimes its just a small spot, other times its larger. Either way, it's pulpy to the touch and I could easily force a finger into it. The windows are original, double hung with an after-market, bolt-on storm. My question is this: Short of replacing all the windows, what is the best way repair this problem? Should I have a pro replace just the base? Or is there a way to fill, sand and seal these pulpy areas? Any suggestions would be appreciated!