Installshield engine (iKernal.exe) could not be launched. RPC server is unavailable

Thanks fro the help from both of you. Here is where we're at with the problem. I ran the Trendmicro housecall to scan the hard drive for viruses and it found bispy.a in a restore class ID. and the Qdown.a trojan in the windows root directory, file C:\edow.exe. I deleted the edow.exe file. Unfortunately the antivirus program on the computer is Norton Antivirus 2004 which I updated to the current virus definition files and it did not detect these trojans. Is there an antivirus checker that will detect and remove viruses that is portable?

I ran services.msc. I get an error message "Interent explorer script error, line 30, char 12 error unspecified, error code:0, URL: res://c:\windows
system32\mmcndmgr.dll\views.htm" I choose to continue and I see the RPC as started.
I checked HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management and it's value is "0".
When I tried to reinstall quickbooks I still get the Installshield engine (iKernal.exe) could not be launched. RPC server is unavailable." error.

My conclusion so far is that there either is or was a virus that has corrupted some system files. I can't remove the virus because the antivirus program on the computer does not detect it. Unfortunately this is a HP computer and the customer cannot locat the retore disk so we can't check the system files. Essentially, this customer is stuck until the HP restore disk is located. Once that is done, we can wipe the hard drive and restore the system. Does anyone have any suggestions to circumvent the no restore disk problem?

Trendmicro did not delete the Trojans. When I selected "clean", the response was it could not delete the infected file. I was logged in as the owner (with administrative rights) when I performed the work. I can't say if the problem started tight after installing SP2. I believe this problem existed for some time. This customer was complaining of problems about 3 months ago. He did not call me in then, but when he could no longer access his quickbooks files or Word files. That's when he infromed me the computer hasn't "worked right" since he installed SP2. I talked to another family member and found out he usued AIM and Bonzi Buddy. I found Gator, Virtual Bouncer, Ad Rotator and StatBlaster on the computer and removed those. His Live Update for NAV 2004 is corrupt and needs to be reinstalled. ( In short, the computer is a mess).
After removing the Spyware, I was able to get one application running correctly, that was PrintShop. Also the executable, OSA.EXE is grabbing most of the CPU (99%). I turned this off via MSCONFIG.

Will give it a try next time I see the customer. I will call him tomorrow.

Thanks for the tip on the TrojanHunter and AntiVir. Trojan Hunter found 2 trojans on my machine here.