Missing standard AVG driver?

Hi!

I tried to install the ATI Catalyst driver to my laptop (AMD Athlon with Windows XP +ATI graphic card), SIS-as I need it to play Sims2 (...) but got the message that I need to install a standard AVG driver first. Hmmm - I was sure I had one! Then tried to re-install it from the CD anyway, but got the message that "VGA driver does not exist". Some one suggested me to re-install the chipset and AVG driver (SIS). But while the chipset installs fine, there's a third error-message saying "InstallRootEnumeratedDriver:Error" when I try to re-install the AVG. These terms are all rather new to me, but regardless what at least I am learning some thing about drivers

I took a look in my device manager and realized that there's a yellow exclamation mark next to one of the driver "standard game port" (that is a direct translation from Danish, to be honest I'm not 100% sure what it is in English). Tried to update it, but it won't allow me to do so. Now I'm sure there's a connection between this yellow mark and my missing VGA driver, but how do I fix all this???

Sound, screen etc are all working fine but this still annoys me anyway as I'm "dying" to play that Sims2 game! Infact my laptop is rather new, all installation original and if it wast for Sims2, every thing would be working fine for me.
Hope some one around here can help me solving the driver-mystery. And let me know if I need to give more info!

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