Logonui.exe system error shell32.dll mising HELP!

I downloaded a icon pack installer yesterday and it told me that i needed a restart for the results to take place... when i restarted my computer it came to the log on screen where i would usually enter my password but the screen was black all that was visible was the cusor, a turn off button at the bottom right and a windows 7 ultimate logo at the bottom.
There's a screen that comes up saying,

LogonUI.exe - System error
The program cant start because SHELL32.dll is missing from your computer.
Try reinstating the program to fix this problem

Can anybody please tell me how to fix this!!?

The following steps may help.

• Use Advanced Boot Options to choose Repair Your Computer.
  
  
• Use the System Recovery Options to choose System Restore.
  
  
• Use OPTION TWO of System Restore to restore your system to before the problems began.

I have the same problem...
When I turn on my PC, the error is:

LogonUI.exe - System error
The program cant start because SHELL32.dll is missing from your computer.
Try reinstating the program to fix this problem

I can't access to the program, what should I do in case of that problem?
Do I need to back up my files and format my computer?that's the only what I'm thinking
or
there's some easy solution to fix it.because I can't access to the SAFE MODE, just to the BIOS set up that I don't know what will I do there...
Please tell me how can I retrieve the SHELL32.dll...

Do the following steps:

• Read carefully through System Repair Disc - Create...
• Use the System Repair Disc to access the System Recovery Options...
• Use the System Recovery Options to choose System Restore...
• Follow OPTION TWO of System Restore and pay close attention to the NOTE: in OPTION ONE step 8.

If that does not resolve it: Troubleshooting Windows 7 Failure to Boot


And if you still need help after all that, please start your own thread.