These appear installing or uninstalling WinZip when the Windows Installer cannot write to the Temp folder. Fixing the folder permissions resolves them. Jump to your situation below or work through the methods in order.
WinZip install errors 2502 and 2503 come from the Windows Installer (MSI) service, not WinZip itself, and appear when installing or uninstalling because the installer cannot write to the Windows Temp folder due to a permissions problem. When you install or uninstall, files are written to C:\Windows\Temp; if the permissions there are damaged, the MSI fails with 2502 or 2503. The fix is to restore access: grant the Administrators and Users groups Full Control on C:\Windows\Temp (and your %temp% folder), clear its old contents, and run the installer elevated. Re-registering the installer service (msiexec /unregister then msiexec /regserver) helps when the MSI engine itself is misregistered. Once the installer can write to Temp, the install or uninstall completes.
Every MSI install or uninstall writes working files to the Windows Temp folder. Errors 2502 and 2503 are the installer reporting it could not do that, the permissions on Temp do not allow it to write, so the package fails partway.
Damaged Temp permissions are usually the culprit, often left behind by cleanup or junkware tools. Granting Administrators and Users Full Control on Temp restores the access the installer needs, and running setup elevated and re-registering the MSI engine cover the remaining cases.
“2502 and 2503 are not really WinZip errors, they are the Windows Installer saying it cannot write to the Temp folder. Every install and uninstall stages files in C:\Windows\Temp, and if the permissions there are broken, usually thanks to some cleanup tool, the MSI dies with these codes. So I give Administrators and Users Full Control on that Temp folder, run the installer elevated, and if the engine itself is off, I re-register it with msiexec. Once it can write to Temp, it goes straight through.”
C:\Windows\Temp, Properties, Security, and grant the Administrators and Users groups Full control.%temp% folder.C:\Windows\Temp and %temp%.msiexec /unregister msiexec /regserver
2502 and 2503 are Windows Installer errors: it cannot write to the Windows Temp folder. Grant Administrators and Users Full Control on C:\Windows\Temp and %temp%, clear those folders, and run the installer as administrator. Re-register the MSI engine with msiexec if the service itself is misregistered.
If the errors persist after fixing Temp permissions and re-registering the installer, take ownership of the Temp folders first (they may be owned by a different account), then reapply Full Control; ownership problems can block permission changes from taking effect. You can also submit your error to us for a tailored fix.