what's your LR version?
Memory related issue is fixed in LR 11.52 & later: http://support.openview.hp.com/selfsolve/document/KM00448984
Try below link
http://msdn.microsoft.com/en-us/windows/hardware/gg487508
After you change the boot.ini to enable 3gb, REBOOT THE MACHINE.
Retry results in analysis