Screen problem on Fujitsu-Siemens laptop

The screen on the Fujitsu-Siemens laptop keeps getting wavy lines on it. I have replaced the memory with new but this hasn’t solved it. My ISP is SKY. My OS is winXP Home. My AV is Kaspersky. The problem exists when I am not on the internet so I think it may be the hardware. Am I right? If so where does the problem Lie and how do I correct it? Many thanks CWalker

Call FSC helpdesk/support and ask them to troubleshoot?