Tools that Check what is slowing down PC and the boot up speed

My Windows XP is getting a bit slow in terms of bootup speed nowadays. Also, when I first click on My Computer item, it takes a while to get it out.

I am thus thinking about the tricks to speed up the booting.

A quick google search can turn up a lot of results, and a lot of tricks. One of the tricks is to use msconfig to reduce the startup item. But I have done that, and filtering out unwanted program. Still I think it's slow.

The question now is, is there a tool that tells me exactly what is slowing down my computers, and how to optimize the speed?

There is a tool called "Bootvis": http://en.wikipedia.org/wiki/BootVis

Bootvis uses in Windows XP built-in routines to analyse your system and rearrange files on your harddrive (see comments). Although these routines are performed periodically by Windows XP, my experience with Bootvis is that it helps speeding up boottimes on Windows XP installations that are running for a while (months or even years).

For your "also" part of the question: I think it will not speed up the start of "My computer". You might try to clean any networking history you might have on your PC for that.