Explorer.exe corrupted or infected by virus

When loading windows, after welcome screen, nothing shows up.
First of all, it is recommended to perform full scan on infected HDD, you can do it connecting the Hd to another computer then do the scanning.

1. Use a virtual disk to access the infected partition, search for any file called explorer.exe and remove all of them.
2. Restart the computer in normal mode, open task manager, go to c:\windows folder, find explorer.exe and rename it. (example: lapiz.exe)
3. Open registry, goto HKLM\software\microsoft\windowsnt\winlogon. Highlight winlogon and identify on the right pane: shell, right click modify, enter lapiz.exe (as in the example)
4. Close registry, then restart the computer.
That should do it

Can't Install .NET Framework 2.0

1. Download the .NET Framework cleanup tool and choose to cleanup the version of the .NET Framework that is causing problems on your system
2. Download and install the version of the .NET Framework that you cleaned up in step 1 (such as the .NET Framework 1.0, .NET Framework 1.1 or .NET Framework 2.0)
3. (optional) Download and run the .NET Framework verification tool to double-check that all .NET Framework files are correctly installed
4. Download and install the desired .NET Framework service pack (such as .NET Framework 1.0 SP3 or .NET Framework 1.1 SP1) by running the setup package directly instead of using Windows Update. Running it directly will allow the service pack setup to display error dialogs instead of having Windows Update suppress them

Error: "QuickBooks has a problem in reading this registration file: qbregistration.dat" after installing an update to Symantec Norton 360

What is happening

When starting QuickBooks, the "Loading QuickBooks..." screen appears temporarily, and then the following error message appears:

QuickBooks has a problem in reading this registration file. You need to ask your system administrator to REMOVE this file and re-install QuickBooks

C:\Documents and Settings\All Users\Application Data\Common Files\Intuit\QuickBooks\QBRegistration.dat

Why is this happening

This error usually occurs if there has been damage to the MSXML component of Windows.

Note: This has been known to occur after installing an update to Symantec's Norton 360 security software suite.
This error may also occur even if Norton 360 is not installed on the computer.

https://support.quickbooks.intuit.com/support/Pages/KnowledgeBaseArticle/1009799

In the Open field, type msiexec.exe /fvaum D:\Qbooks\msxml.msi (replace D with the letter assigned to your CD drive) and click OK