Before you migrate your system to perform analysis of 64-bit Microsoft Windows 7 Upgrade Advisor can use the software offered free of charge.
This application scans your computer to show you that how much your software is compatible with your hardware. And This aplication shows you potential factors that could cause some problems and also reveal to slowdowns in the system
Also to check motherbord is very important, if you start to use 64Bit to use ram more than 4GB, You have to know whether your motherbord supports to 64Bit.
You can learn with SiSoft Sandra the properties of the motherboard .These values are shown to you based on your motherboard chipset.Some Motherboards are may be brought to the restrictions to be used less memory than chipset supports.
BIOS code can be eliminated in some cases, memory constraints, specifications subject to change.
If everything is alright we can proceed to the question of whether to use compatible software. Now applications support 64-bit. Some of them really benefit from 64-bits, but it only works with some of them by simulating it.