None of them worked, but I think that I am one step forward, because I realized that when I go to msconfig > boot.ini > Advanced Options and click MAXMEM, it shows 933 and If I try to change it to a higher value, and click "OK", and try opening it again or restarting the Computer is back to 933, but if I change it to lower value it works. The same happens and when I try manually editing C:\boot.ini and type /maxmem=3072, and restart the pc it again changes back to 933 Does someone know how to fix this?