VPN client crashes my Inspiron 6000

I tried installing Nortel VPN client CVC465 on my Inspiron 6000. Everything is fine until the computer is re-booted. Basically I couldn't boot - after the Dell logo a blue screen comes up saying that something has been disabled to protect my computer and etc, and I'm stuck. The only way to recover is to restore to a good known state before the VPN client installation with Windows XP's system restore.

I read somewhere that it could be the Intel PROSet Wireless drivers (I have Intel Pro/Wireless 2200BG in this Inspiron) conflicting with the Nortel VNP client. Is this the cause? Has anyone ever been able to get it work with Inspiron 6000?

Thanks in advance.