need for speed most wanted help

[shibby2000]

i recently got need for speed most wanted and underground 2 but after a random amount of time both of them freeze and i usally have to restart my computer i have asks ea but there help sucks

Windows xp home service pack 2
Intel pentium 4 3.2ghz
1gb ram
Ati Radeon X740XL 128MB
Plese help i am deperate to play them