I am afraid your link doesn't work :(
What make of computer is this? If it is a brand name like HP, Dell, Acer, Lenovo or whatever you are probably limited, and will need to get recovery disks from them.
If it is a small builder or DIY job then you should be able to do a repair install using a similar XP CD and your COA.
What intrigues me is the blue screen. Normally in these circumstances I would expect it to be black with possibly a little white cursor in the top left corner.
- A BSOD always comes with an error message in white characters.
- The fact that you can get into things via Task Manager tells me that Windows has loaded.
- This suggests to me that the problem is with loading the desktop, and, as it is the same for all users this is the general desktop handling mechanism, not the user profile.
Try going into <display properties> and <desktop>. Down the bottom tight you will see a box labeled "color". Is the default blue the same colour as you get on bootup?.................it is not as bright as a BSOD
As it will only take a few minutes, you might try changing the theme, desktop and wallpaper and see if that has any effect.
Another thing I would try is hitting the Windows Key + R. This should bring up the run prompt (if not go through Task Manager). Type sfc /scannow run it (note the space and double "n").
You will need an XP installation CD of the same type (Pro/Home & SP), and it will prompt you to insert one.
You should get the message:
"Files that are required for Windows to run properly must be copied to the DLL cache"
It will then run the Windows systems file check and hopefully fix any problems.
