slow program problems

Hey guys my sister's laptop computer has had some real problems with slow programs. First of all she plays the Sims 2 and sometime she gets a message that the game has crashed, the game also runs pretty slow, and she also gets a message telling her the battery is low and she should change it or change the outlet she is using. i checked the system and it says the battery is at 98% power, and it is pugged in the AC.
another thing is that every program she has seems to be running very slow. the load bar on the bottom of the internet screen just loads half way and all she gets is a white screem, no message no nothing.
we called the makers of the computer, which is a Balance laptop, with a 40GB hard drive and has 334MB RAM. the guy said that we should expand the memory.
now we've expanded the virtual memory. but the programs still run slow. i was wondering if you guys can help, you've never given me bad advice when i have a problem.
lastly i have a bit of a question, i found this thing on her computer (while i was was trying to fix the above problems) called a disc defragmenter. i read the help guide on it and was wondering could running the disc defragmenter cure the computer of the slow programs?
so if you can help i would greatly appreciate it!
P.S. i have already run AD Aware, norton anti-virus/anti spy, spy-bot and yahoo anti-spy. and have cleared the computer of all that they found but the problems are still there!

 

Old model laptop is usually limited VGA ram, do you think it get enough for Playing game ?