help me please

[youthis_14]

i've already installed PES 2008 and it's running well..after that i tried installed PES 2009 DEMO n its work too..but when i tried to run PES 2008 i've mesagge my memory it's to low and PES 2008 run not so good (its like i have low memory). I removed PES 2009 DEMO n PES 2008 and i've deleted the registry too.. after that i've installed PES 2008 again but still i've message the memory its low.. my computer spesification is : Intel Core 2 Duo Processor T7500 (2,2 Ghz), 2 Gb Memory and 512 MB VGA..
Please someone help me to solved my problem because i can't play PES 2008...