hi to all, i made this thread so u cud help me,cos i just upgrade my ram from 512 to 1024 Mb,after that windows does start but it doesnt completely open i mean
all i c is the "loading WINDOWS XP logo" after that a black screen
so wat do i need to do to restore my old stat without losing any files

my pc is old 4 year now
its a Sony vaio pcv-rs702 desktop
with a dual channel ram DDR SDRAM 512mb(256x2) DDR400 PC3200
and made the upgrade adding a 512 MB Ram DDR400 (3208GATA01-04b4)

im just a newbie upgrading pcs..now i have this problem but i dont know what to do
or wat i have done..
hope ur replys

Try changing the slot in which the new module is placed.
Many mobo,s are particular about the order in which memory modules are installed.
Remove older modules and try with only new one in slot nearest processor.
If this does not work then try another slot.
If successful add older modules one at a time and boot.
If at any time problems occur then it should be possible to identify faulty module/s

same problem
loading then a black screen...

My initial guess is the same as the previous poster. Most boards have the slots marked (in tiny letters next to the slots) slot 0, slot 1, slot 2, etc. Use slot 0 first and work your way up. Memory is very volatile (no pun intended). It doesnt take much to fry them. They may have been good but in the process of handling if they were exposed to ANY static...IF you have another machine around, try the mems in those to ensure they ARE good.