[RaceBannon]

compac presario, about 6 years old windows vista 4 gigs ram 1.5 gigs in use, the rest shows available

[SouthernBoyupNorth]

My advice is to save what you can documents and picture wise and format the damn thing. Either that or buy a new one.

[E. Pluribus Unum]

I agree. Every few years you should do a clean install, whether you need one or not.

[kingu]

You need to find out what the rundll32 process is wrapped up around. rundll32 is just a wrapper; I’m going to bet that it is your anti-virus which is doing a full scan of the computer, but it could be something more...

Go to this page, follow the information, figure out what is really running.

http://www.howtogeek.com/howto/windows-vista/what-is-rundll32exe-and-why-is-it-running/

[Jeff Chandler]

The Task Manager should show you.

Control Alt Delete

[Oshkalaboomboom]

The Windows Task Manager can show you a lot of information about what programs are running, and usually it does what you need it to. But on the rare occasions you need more information—like if you're trying to figure out which program is using your webcam, for example—you need Process Explorer. Process Explorer is one of the many Task Manager alternatives out there, offering information on what files are currently in use, what hardware, and what each program is doing. If the regular Task Manager isn't giving you the info you need, Process Explorer will. Freeware.

Get it here

If you look on that same page, over on the right where it says Learn More there is also a link for a command line dll viewer. Hope this helps.

[smokingfrog]

http://www8.hp.com/us/en/campaigns/hpsupportassistant/hpsupport.html

[Scutter]

Rundll32.exe is an executable that loads a dynamic link library (DLL) that contains the actual functionality. SO it is sort of a wrapper that doesn't do anything but load some DLL and invoke an exported function in it. For older versions of Windows, like Vista, a lot of the operating system services were implemented as DLLs that were loaded and run by Rundll32.exe. So you need to find out what DLL the troublesome instance of rundll32.exe is loading in order to know what the issue is.

This article provides very clear instructions on how to determine what is going on.

BTW - looks like rundll32.exe was removed from later versions of Windows (at least I don't see any instances of it in Task Manager on my Windows 8.1 laptop) - probably for this exact reason.

[Lou L]

I had this happen a little earlier in the year. Download/upgrade to the latest malware bytes and run it in safe mode with networking. It’s an insidious “bot” adware or something like that.

[sickoflibs]

I am no expert but had a similar problem on my last computer an HP with Norton which was Vista upgraded to windows 7.

I found a bad flash player add-on to explorer was causing some of it.

The problem is you risk a burned out motherboard from overuse.

Did you try bringing it up in safe mode?(I know this is basic)

[The Great RJ]

I would try to run an AVG Rescue CD. Here is a video on how to do this.

[Dalberg-Acton]

It could be auto update. Try turning that off temporarily.

[angryoldfatman]

HP COMPAQ KNOWN PROBLEM WITH 80% TO 100% CPU - POWER CABLE!

My wife encountered exact same problem with her HP Compaq 6710b. I just about pulled all my hair out trying to figure out what was wrong.

COME TO FIND OUT...

HP Compaq laptops sometimes will max out CPU when AC adapter partially fails / doesn’t deliver enough juice.

DIAGNOSE: RUN LAPTOP ON BATTERY AND SEE IF IT SPEEDS UP! IF IT DOES, REPLACE THE AC ADAPTER!

[raybbr]

Try Glary Utilities. It’s a suite of tools that works.

[Zhang Fei]

Run Housecall:

http://housecall.trendmicro.com/

It will remove any viruses it detects.

Download and run SuperAntiSpyware:

http://www.superantispyware.com/download.html

Download and run Malwarebytes:

http://www.malwarebytes.org/mwb-download/

[PieterCasparzen]

What about network traffic ?

[PieterCasparzen]

If you physically unplug the network connection while this is going on, you may see cpu usage level change.

I googled

rundll32 vulnerabilities

and found that it is a prime target of malware.

[minnesota_bound]

Run superantispyware from http://www.superantispyware.com
Download the free edition, select the trial pro version during the install. Make sure to uncheck the extra toolbars they try to get you to install.

It may be spyware you have that is causing this.

[Organic Panic]

Make a list of running services in the back ground. Then reboot in safe mode and compare safe mode services. There are probable dozens of oddball serrvices that are viruses or othr grey area junk that can go. Also make sure your hard drive isn’t full.

[Secret Agent Man]

try a system restore to a date prior to your trouble starting.

[Mr. K]

4Gig of ram is not good- upgrade it to 8 and you’ll notice some major improvement too

Stupid Microsoft bloatware operating systems is using most of that