I've had a problem show its ugly face on my main home PC lately. When I log on to the Internet (Net Zero dial-up) after a short period (1-5 minutes) I get a box that pops that says I am having a Remote Procedure Call (RPC) that cannot be executed, and my system will be shut down. I get a counter from 60 seconds and when it reaches 0, the system shuts itself down. My system is an Athlon 2000+ custom built by me. I'm running Windows XP. I've been having some other small problems with the computer so I figured it was time for a Windows reinstall. I did that last night (not a complete HD format and rewrite, I simply had XP delete the /windows directory and rewrite XP). Once I got it back up and drivers reinstalled, I logged on to the Internet and the same thing happened. So my question is, what is going on? My theory is that I may have some harmful code on the HD (virus, Trojan horse, etc) that was not in the windows directory, and it is trying to ask my PC to do something it doesn't agree with. I currently *do not* have any up to date antivirus software on the machine (don't flame me, please, I know this isn't good. My theory was that since I didn't download any software directly to the machine due to the slow connection, but rather downloaded it on my work pc which is fully up to date, checked it, then transferred it to the home pc, I was OK. Probably not the best idea now that I think about it). So I'm also going to ask for a good freeware/open source antivirus software recommendation as well. Anyone have any ideas on what is happening to get that Remote Procedure Call error and shutdown? What can be done to eliminate it so I don't have this problem? Thanks for any input. EDIT: A little google goes a long way, so I guess my main question involves a good antivirus solution for my machine: New Remote Procedure Call Exploit (07/31/03) Microsoft recently announced a security patch for Windows NT, Windows 2000, Windows XP and Windows Server 2003 operating systems. This patch corrects a security problem with the remote procedure call (RPC) function. The RPC function permits a remote computer to execute code on another computer. It is strongly recommended that this patch be installed. We have received reports that may indicate active attempts to exploit computers running the above operating systems that lack the Windows MS03-026 patch.