Posted 17 June 2009 - 10:55 AM
Windows 7 should be released for sale shortly.
If it were me & I could possibly wait I wouldn't buy until Windows 7 is out.
Now to answer your questions [the best I can]
Vista 64 bit can use more then the 4GB of memory you want.
Not all programs/applications that work on 64 bit XP will work on 64 bit Vista.
You need to check the software manufacturers web site to get the compatibility information.
"Is there any difference in term of performance between home premium and business."
I can't answer that one as I have never used the Business version.
OCZ StealthXstream 700W,Gigabyte GA-EP45-UD3R , E8500, Arctic Freezer Pro 7, 3GB G.Skill PC8500,Gigabyte Radeon HD 4850 OC [1GB ], Seagate 250GB SATA II X2 in RAID 0, Samsung SATA DVD burner.