How do i fix boot on my laptop

Seems that adware ,spyware or a virus caused this.
I found a solution that could work from this forum :
http://www.geekstogo.com/forum/Windows-XP-Logs-Then-Immediately-Logs-Off-t15771.html

It's an advanced technique and you will need your Windows XP setup CD.

Boot using your winxp cd.
Enter recovery console.(press R on first screen)
at the command prompt go to

C:/windows/system32

next type:
Dir *.exe

If you find, it, type

copy userinit.exe wsaupdater.exe

Exit and reboot normally. You should now be able to logon.

Run regedit

Navigate to
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\

In the right pane, you should see

C:\WINDOWS\System32\wsaupdater.exe,

Change it so that it reads:

C:\WINDOWS\System32\userinit.exe

That should solve the problem

What's wrong with it? Give me some details.