Having Problems with XP Service Pack 2 ater installation .. Can't install any software or Uninstall

I have a Dell Latitude C840 and I had XP Pro installed and everything
was fine until I loaded Service Pack 2 and now I can't install or
uninstall any InstallShield based software and also I can't view Disk
Management console in Computer Management.

When I try to install software I get error message saying
"InstallShield Engine (ikernel.exe) could not be launced The RPC server
is anavailable"

So I added ikernel.exe to startup and still no luck I get error's like
"An error occurred while launching the the setup The remote procedure
call failed"

I made sure this RPC thing is on automatic and started in Services and
it still does it. I have tried everything I could find on the web and
can't fix this problem. I have tried re-installing InstallShield but it
gives me same error about RPC.

I have tried removing and insalling SP 2 with no luck and I have no
clue what it could be. I just remembered one thing I don't know if this
could of did anything. I had disabled my Wireless connection and
possibly Ethernet connection since I don't use those and I believe I
had those disabled when I installed SP 2 I don't know if this would of
made any difference.

Also in my Event Viewer I see error saying something like "Failed to
connect to server. Error: 0x800706BA" My laptop does not have any
server attached to it it's just stand alone unit and nothing fancy
attached to it.

I have other Dell laptop which is almost identical it's just C800 and
running XP Pro SP 2 on it and no problems at all. Maybe I can copy some
folders from it and move it to this one. But I am not sure which
folders should I be concerned about.

If anybody have any clue please let me know I would appreciate any help
since I am trying to install some software and want to configure my new
external hard drive to back up my laptop. Please help me I really hate
to uninstall SP 2 since my media player does not work after that and
possibly some other software and I hate to loose all my Media library
and preferences.

Thank you all in advance!