You may have the following problems:
1. When you open a new Visual Basic project, the PC tell you that Visual Basic Editor faced some problems and thus the program is terminated
2. When you try to open a Windows Form in Design Mode, the Visual Studio hangs.
The problem is not fixed even if SP1 is installed, why?
It is because you have installed and used Applocale, which have corrupted your OS's registry (once the font display is abnormal when you further use Windows Installer)
To solve this problem, it is impossible. You have to install a new OS (so that your registry is clean) then install Visual Studio 2005 into it. Note that you should NOT install .NET framwork 3 because the font cache of Windows Presentation Foundation will slow down your booting speed.
To prevent further corruption of registry by Applocale, go to %windir%/AppPatch, then find any .tmp files, clear all contents in it using Notepad (making it 0 bytes), then save it, and set it as Read only. Then reboot it.