Programs and Safe Mode won't run, Rundll32.exe won't close?

Are you actually inducing your PC to go to Safe Mode using F8 key at System Boot. This is sometimes difficult to achieve if you’re not used to doing it.

If you’re able to boot normally to Windows XP then you can alter your boot mode using System Configuration Utility, sometimes called “msconfig”. This is rated as an easy
task. Follow the instructions below:

1.Click on Start and then Run.

2.In the text box in the Run window, type msconfig and click OK. This will open the System Configuration Utility program.

Note: Do not make changes in the System Configuration Utility other than those outlined here to avoid causing serious system issues. This utility controls a number of startup activities other than those involved with Safe Mode.

3.Click on the BOOT.INI tab located at the top of the System Configuration Utility window.

4.Check the checkbox next to /SAFEBOOT and click OK.

5.You will then be prompted to either Restart, which will restart the PC immediately, or Exit Without Restart, which will close the window and allow you to restart the PC manually.

6.After the restart, the PC will automatically boot into Windows XP Safe Mode.

Note: Windows XP will continue to boot into Safe Mode until the System Configuration Utility is configured to again boot normally.

7.When your work in Safe Mode is complete, click on Start and then Run. Type msconfig in the text box and click OK.

This will again open the System Configuration Utility program.

8.Choose the Normal Startup radio button and click OK.

9.You will then be prompted to either Restart, which will restart the PC immediately, or Exit Without Restart, which will close the window and allow you to restart the PC manually.

10.After the restart, the PC will boot into Windows XP normally and will continue to do so.

OK, now that you’re in SAFEMODE, you will need to RESTORE your system to an earlier time when your PC was working like it should. Let the System Restore function do its thing and when it Reboots back to SafeMode, go ahead and run your AntiVirus scans. Make sure that your McAfee virus definitions are up-to-date. I would suggest doing more than 1 scan just to make sure that all virus have been detected. Personally, I would use 3 different antivirus/anti-malware apps to clean an infected system.

I won’t add to that, but a word of advice; do not try to kill rundll32.exe with task manager. That’s the program that starts many of your services, including ones that are essential to Windows.

I don’t think your AV did a thorough enough job of deleting your bugaboo, since the behavior you’re describing is typical of how viruses defend themselves from removal attempts. On the off chance that you have your original OS install disks (I hope you are talking about XP here), I would go into your system BIOS and set it to boot from CD-ROM. When you get the prompt to install Windows, follow through – you’ll have to go several screens in – until you get to a screen that asks you if you want to reinstall Windows or repair your existing installation. This is NOT the option to go to the recovery console. Tell it you want to repair your existing installation and see if that gets you to a point where you can at least boot into safe mode.

More here: http://www.ehow.com/how_5130638_repair-existing-windows-xp-installation.html