OpenOffice error when opening a document

I have installed OpenOffice on my Computer running Windows 7. Yesterday when I try to open my saved OpenOffice document an error occurred saying sal3.dll is missing.
I don’t know what’s causing this I’ve tried to reinstall the software but still it gives me the same problem.
How to get rid of this issue?

soffice.bin – System Error
The program can't start because sal3.dll is missing from your computer.
Try reinstalling the program to fix this problem.
