_ISSetup.dll is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like _ISSetup.dll, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like _SETUP.EXE - to follow. These files were created so that multiple programs (eg. Realtek RTL8187B Wireless 802.11b/g 54Mbps USB 2.0 Network Adapter) could share the same _ISSetup.dll file, saving valuable memory allocation, therefore making your computer run more efficiently.
Unfortunately, what makes DLL files so convenient and efficient, also makes them extremely vulnerable to problems. If something happens to a shared DLL file, either it goes missing or gets corrupted in some way, it can generate a "runtime" error message. Runtime is pretty self-explanatory; it means that these errors are triggered when _ISSetup.dll is attempted to be loaded either when Realtek RTL8187B Wireless 802.11b/g 54Mbps USB 2.0 Network Adapter is starting up, or in some cases already running. Some of the most common _ISSetup.dll errors include:
- Access Violation at address - _ISSetup.dll.
- _ISSetup.dll could not be found.
- Cannot find C:\Program Files (x86)\InstallShield Installation Information\{7095FD27-37F0-4750-9DE8-D37DC0043706}\_ISSetup.dll.
- Cannot register _ISSetup.dll.
- Cannot start Realtek RTL8187B Wireless 802.11b/g 54Mbps USB 2.0 Network Adapter. A required component is missing: _ISSetup.dll. Please install Realtek RTL8187B Wireless 802.11b/g 54Mbps USB 2.0 Network Adapter again.
- Failed to load _ISSetup.dll.
- The application has failed to start because _ISSetup.dll was not found.
- The file _ISSetup.dll is missing or corrupt.
- This application failed to start because _ISSetup.dll was not found. Re-installing the application may fix this problem.
Your _ISSetup.dll file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with Realtek RTL8187B Wireless 802.11b/g 54Mbps USB 2.0 Network Adapter), or deleted by a malware infection. Furthermore, _ISSetup.dll file corruption could be caused from a power outage when loading Realtek RTL8187B Wireless 802.11b/g 54Mbps USB 2.0 Network Adapter, system crash while loading _ISSetup.dll, bad sectors on your storage media (usually your primary hard drive), or quite commonly, a malware infection. Thus, it's critical to make sure your anti-virus is kept up-to-date and scanning regularly.