There may be something starting up as Windows boots that may be causing the problem.
I'd like to see a list of programs loading when your PC starts, so please post a screenshot link.
To do this:
1. Start > Run > type msconfig > Press OK. On the SCU window that opens, click the Startup tab. Widen the Command column so the full paths are visible (as in 2nd link below).
2. With only the SCU Startup tab displayed, press the Prt Scr (one half of Sys Rq) button on your keyboard.
3. Open your image editor & Edit > Paste / Import the image into the program (crop as necessary if you know how, otherwise let it be), then save it as a picture file.
4. Go to click here & host the file - it's free. (If you have a long list, you may have to post it in 2/3 pics or, use your image editor to 'stitch' them up, then you can host it as a single pic).
5. Finally, post the link here.
If you have any problems with the above, just let us know.
As an example, my Startup list (WinXP Pro) looks like this: click here. As you can see only a handful of programs & PC starts up fairly quick, in just over a min. G