El estos dias fue caótico para los usuarios de Windows XP que tienen instalado el antivirus AVG, sea en su versión gratis o profesional. Por un problema en la actualización de la base de datos, el antivirus confundió al archivo user32.dll, crítico para el funcionamiento de Windows, como infectado por un virus. Como consecuencia ha habido una gran cantidad de ordenadores que no pueden iniciar el Sistema Operativa.
Enseguida se dieron cuenta y pusieron las posibles soluciones que os pongo a continuación, aunque están en Ingles y no entendamos muy bien lo que hay que hacer, lo podemos traducir el texto con las Herramientas de traducir de Google http://www.google.es/language_tools?hl=es
False positive "user32.dll" (DB: 270.9.0/1777)
In case you are not able to run your Windows XP operating system after AVG 8.0 virus definition update, it may be caused by a false positive on a specific "user32.dll" system file. The file was moved to the AVG Virus Vault and deleted. Therefore it is not possible to start Windows. Please follow the steps below to rectify this situation:
1. Please insert the Windows XP installation CD and boot computer from this CD (if you do not have the installation CD please follow steps mentioned in our FAQ 1575).
2. Choose and run Recovery Console.
3. Choose Windows operating system you want to repair.
4. Disable AVG Resident Shield from loading. You can disable loading services/drivers with "disable" command, i.e. you have to type the following commands (some
of them might not be present in all AVG editions):
5. Restore the User32.dll file from the Windows XP installation CD (instead "D:" use letter of your CD-ROM drive):
expand D:\i386\user32.dl_ c:\windows\system32\
In case the command fails, please use the following command to rename original user32.dll and repeat the command above.
ren user32.dll user32.bak
6. Restart computer and boot Windows normally.
7. In order to re-enable the AVG Resident Shield services we recommend that you perform the AVG repair installation as follows:
– Download the latest AVG installation package from the following webpage and save it on your hard disk:
– When you are prompted, please do not open this file directly from the internet, but click the Save button and choose a location, where the installation
file should be stored. We recommend saving the file to the Desktop.
– Restart your computer.
– Locate the downloaded AVG installation file (it has a four color square icon and its name starts with AVG_…) and launch the installation by double-clicking on it.
– Follow the installation wizard.
– When prompted, please select the Repair installation option.
– Enter your license number when you are asked (we recommend that you use the copy&paste* method to enter this license number into the installation form).
– Restart your computer and update AVG.
False positive "user32.dll" – fix tool
In case you you are not able to run your Windows XP operating system after AVG 8.0 virus definition update (DB: 270.9.0/1777) and you do not have Windows XP installation CD, please proceed as follows in order to resolve this situation:
We have prepared an utility which can fix the issue mentioned above. You can use the following boot media: either CD-ROM or USB flash drive. If you decide to use CD-ROM, please follow the instructions in part A), in case of USB flash drive follow the steps in part B). When finished it is neccessary (in both cases) to follow additional instructions described in part C).
A. CD-ROM instructions (recommended):
1. Please download the CD image.
2. Use your favourite CD burning software to burn the downloaded image (IMPORTANT NOTE: Please use the "Burn CD from image"* option).
3. Insert the CD into the CD-ROM drive of the affected computer and restart the computer. It should boot up from the CD. If not, please see the user’s manual for you motherboard to find out how to let the computer boot from a CD.
4. Continue with instructions in section C).
B. USB flash drive instructions (available only for computers supporting USB boot function):
1. Please download the USB flash archive (rescue.zip).
2. Extract the content of the "rescue.zip" archive to your USB flash drive.
3. IMPORTANT: go to the root of the flash drive.
WARNING: take care to do the next step only when you are located on the flash drive. Doing the step on the local disk can DESTROY BOOT FILES ON YOUR HARD
4. Please run the "makeboot.bat" batch (pay attention that it is the one on the USB flash drive) and follow the instructions.
5. Connect the USB flash drive to the affected computer and restart the computer. It should boot up from the USB flash drive. If not, please see the user’s manual for you motherboard to find out how to let the computer boot from a USB flash drive. Please note that this function is not supported on all motherboards.
C. Additional instructions:
1. Boot the computer from the CD-ROM or USB flash drive as described in steps A) and B).
2. Follow the rescue process.
3. Please login to Windows as Administrator.
4. Update the AVG program (Open AVG User Interface and click the "Update now" button)
5. Rename the file "avgrsx.exe_off" to "avgrsx.exe". This file is located in the AVG 8.0 Program folder (C:\Program Files\AVG\AVG8 by default)´.
6. Rename the file "avgsched.dll_off" to "avgsched.dll". This file is located in the AVG 8.0 Program folder (C:\Program Files\AVG\AVG8 by default)
7. Remove the boot media (CD-ROM or USB flash drive) and restart your computer.
* The name of the function may vary depending on used software.