for the battery.
No I did not say that you could USE the existing stick that you have with the DDR2.What I said was that DDR2 allows you the use of different ram values to maintain Dual channel capabilities. This means that the sticks of ram do not have to be identical as in size like other dual channel capable systems. But they would have to be the same speed. Your existing 512megs is set at 400mhz and is regular DDR. DDR2 on your system requires a 533mhz setting. Although the DDR2 is backward compatable and should work on the 400mhz setting it will (by default) only operate at the lowest speed of the installed ram sticks.
What I suggested was to purchase the 1 gig of DDR2@533mhz ram to upgrade your system and thus removing the existing ram.
The best programs that are availlable to improve any system is anti-virus and anti spyware/malware utillities. There are many sites that are availalable to get these from. This is one of my most favorite sites for software
it is the main mirror site for most software)
note*** there is little difference between performance between purchased programs and free ones. What I use is:
spywareblaster, spybot s&d,adawareSE, Ccleaner, and AVG, and winpatrol.
Good luck with your new notebook