When I open a vi, I get this error below.
Have you searched to see if you have the PackSystemLib.dll on your computer? Where did you get this code?
Based on what you have given us which isn't much I would suggest that you do not have something installed that you need.
I reinstalled the system and labview, then got this error. It's ok before.
Obviously, you did not install all the required items. This dll is most likely not something that is part of LabVIEW. What does the program do? (e.g. communicate with some non-NI hardware or similar). Did you install the third party drivers?