KB982670 .Net Framework 4 Client Profile slows down WinXP Boot time.

Solution to this problem

When .NET redistributable is installed, it compiles the high priority assemblies in 5 to 10 minutes and then waits until your computer is idle to process the low priority assemblies. The following method forces all of the remaining items to be compiled with a command called NGEN.exe. Follow these steps:

1) Run cmd.exe from Start > Run

2) Type cd\

3) Type cd Windows\Microsoft.NET\Framework\v2.0.50727

4) Type NGEN executequeueditems and press Enter

5) It will take about 10minutes depending upon system speed. After the process is complete, the following prompt will appear in the command prompt

C:\Windows\Microsoft.NET\Framework\v2.0.50727>

6) Type exit to close the command prompt.

After performing these steps, your computer will boot up at usual speed.

NOTE:

The directory v2.0.50727 may be different if no earlier versions of .NET framework were already installed. It will be v4.0.30319 with only the version 4 present.