Problems with a Rootkit

I'm trying to fix my granddaughter's laptop and have discovered it has a rootkit.

Before coming here I ran Rootkit Revealer (probably misspelled because I can no longer find the file.)

It found 2 rootkits.
I could not copy them and wrote them down but can't find the note now.
Both of them started with C:/ProgramFiles HKLM Security .
I can run the rootkit revealer again if you want.

I've gone through all your steps and failed to clear the root kit.

Here are the details.

Dell inspiron 5150 with XP SP3

Uninstalled
Viewpoint Manager (remove only)
Viewpoint Media Player
Viewpoint Toolbar
LoudMo
Removed old Sun Java and updated Java.

Got a Windows pop up box saying it can't run:

C:/ProgramFiles/WildTangent/Apps/CDA/cdaEngine0400.dll
Later found that file in the Hijackthis log and deleted it.

Ran SuperAntispyware Scanner.
It showed a Q drive in the window so I also checked it.
SAS found an adware helper and fixed it.

A window trying to install "Solutions Center" kept poping up and HP Solutions in the icon tray showed it was constanly running so I uninstalled all HP Printer software.

Ran ComboFix.
Ran RootRepeal but never got past the Initializing Window and had to shut down the computer with the power button to get out.

Ran MGTools.
Ran Gmer but it frooze up and I don't think I got a log file.
Ran Bitdefender
Ran Sophos Anti Rootkit 1.1
Ran Panda Root Kit
Installed Zone Alarm (which I had uninstalled earlier because it was taking close to an hour to load.

My granddaughter uses this for her school work so I'd like to get it fixed as it is running very slow now and the hard drive churns for about 1/5 hour after booting up.

Thanks.