When i boot up my computer it takes quite a long time to load after post to the logon screen, it just stays as a blank screen for 30secs-1min or so until the windows logo and loading bar appear. It didn't do this when i first installed vista ultimate and i'm not sure if i caused it, don't know how i could have. Everything else is working fine just thought this was strange and is somewhat annoying. Any ideas?
Drivers hanging out form now uninstalled hardware, bad drivers, and lots of garbage in the Start settings will cause the kinds of slowness you are talking about. Don't bother to reinstall, you may not get all the garbage and only make the issue worse. Clean it up, instead.
try this - click start, type in "Performance Information and Tools" (without the quotes). Then, click on the "Advanced tools" link on the left side. At the top of the screen, see if there is anything listed under "Performance issues" - if you have any program that is taking too long to startup, it 'should' get identified here.
Also, is your antivirus up-to-date? And if so, when did you last scan (full) your system?
As Mazuk susggested, use msconfig to see what is starting up and see if you can disable unnecessary stuff.
What is your config (CPU/RAM/HDD)?