|So do you only get the splash screen or does it get to the desktop with Icons then freeze? |
If the latter you may want to check the apps you have to auto-run. You can simply do a regedit and go to HKLM\software\Microsoft\windows\current version\run. This is where all of the apps that auto-run on start up are.
You can review each one to see if they are valid by Googleng them to see what they are. If you have one you have a question about or think is the problem, post it back and we can see if it is.
You can also think back to when it started and if you installed any thing then. If you did you may want to uninstall it to see if it is the problem.