"I have a new computer ....."
If it's shop bought then contact the store you bought it from or the manufacturer.
Tell them you have run the Memory Checker and have faults reported.
The memory checker runs before Windows starts up and is testing the RAM modules for any bad sectors.It's looking for hardware faults, either manufacturing defects or signs of failure in ageing memory modules.
This is very important with VISTA as it uses all the RAM all the time in a randomised fashion (to boost security).
If there are any bad sectors on one of your RAM sticks then VISTA will try to use them and you might get system crashes.
You need to get the system checked out and any bad sticks of RAM replaced.