I guess your comp badly needs a clear-up.
And about the slow start-up,There can be a variety of reasons.
Try this.Go to Run, type msconfig and hit enter. Under the ‘Start Up’ tab, uncheck the unwanted programs and press OK. Things should be a bit fine the next time Windows boots.
Another program worth mentioning here is Glary Utilities which will help in setting after how much time programs should be loaded after Windows boots.
It has a startup manager module. It's free and has a bunch of other useful tools. I've been using it.
That I exist is a perpetual surprise which is life