Use MSCONFIG to limit your startup applications.
Start - Run - Type msconfig - Startup Tab - Untick the one's you don't need (most you will recognise)
** I have Win 7 and I only have 2 ticked - my Antivirus and wireless mouse in startup **
THEN restart your laptop. It it starts up okay then this indicates a conflict. It then means that it can be a lengthy process to find the culprit by putting ticks back (one at a time) and restarting until you find which it is.