Hello,
Lets try the following:
1. Open Windows Explorer.
2. Click Tools > Folder Options.
3. Click the View tab.
4. Choose "Show hidden files and folders".
5. Clear the check box for "Hide protected operating system files".
6. Click Apply and OK.
7. Browse the C: drive in Windows Explorer.
8. Right-click on the arcsetup.exe file and choose Properties.
9. Click on the Security tab.
10. Make sure the Everyone group has the Full Control permission to this
file.
If the Everyone group has already had the Full Control permission, please
temporarily rename arcsetup.exe to arcsetup.old. Then restart the computer
and try
to install SP4 again. If any other problem occurs, rename the file back to
arcsetup.exe and restart the computer.
Regards,
Ken Simmons
Microsoft Technical Support for Platforms and Business Applications