Same here; we don't use the Windows IME much; instead, we use a program called Key. It's like a self-contained word procesor. You type the pinyin (sans tone, unless you really want to), then at either word break or sentence break depending on your settings, it converts everything to characters, based on a database of most common usage. If the wrong character is added, you just select it and open the homonym finder, then select the proper character. It also includes a searchable dictionary, recordings of all the syllables that play with the tool-tip definition and pinyin you get when hovering over a character, and a radical finder, where you construct a character by the radicals you remember (if you don't remember the pinyin, for instance). I also believe it has plugins for Korean and Japanese ...