How do I fix FSX installation error 1607?

Microsoft Flight Simulator X (FSX) installation error 1607 means the boxed simulator’s InstallShield scripting runtime could not start or register. Restart Windows, run setup.exe as administrator, then repair Windows Installer and rename the shared InstallShield Driver folder so setup can rebuild it. Steam Edition normally uses a different installation process.

The full message usually reads -1607: Unable to install InstallShield Scripting Runtime. It occurs before FSX is properly installed, so activation changes and service packs will not repair it.

Does error 1607 affect boxed FSX or Steam Edition?

Error 1607 primarily affects the DVD editions of FSX because they use a legacy InstallShield installer.

If the edition is unclear, our boxed-versus-Steam installation breakdown explains which repair and update methods apply to each release.

Fix FSX error 1607 in this order

1. Restart Windows and use an administrator account. Close every installer, restart the PC, open the first FSX disc in File Explorer and run setup.exe as administrator. Launch it directly rather than through AutoPlay. Clear any compatibility mode previously applied to the installer; Windows XP compatibility does not repair a damaged InstallShield runtime.
2. Check the installation media and temporary folder. Press Windows key plus R, enter %temp% and remove the files Windows permits you to delete. Confirm that the system drive has free space. If the DVD is slow or produces read or CRC errors, copy its contents to a simple local folder such as C:\FSXInstall and run setup there. A failed copy points to the disc or optical drive, not InstallShield.
3. Repair Windows Installer registration. Open services.msc and make sure Windows Installer is not disabled; Manual startup is normal. Then open Command Prompt as administrator and run msiexec /unregister, followed by msiexec /regserver. Restart Windows before trying FSX setup again.
4. Reset the shared InstallShield Driver folder. Close setup and locate C:\Program Files (x86)\Common Files\InstallShield\Driver on 64-bit Windows, or C:\Program Files\Common Files\InstallShield\Driver on 32-bit Windows. Rename Driver to Driver.backup, then rerun setup.exe as administrator. Do not delete the whole InstallShield directory; renaming the driver is reversible and allows the FSX installer to create a fresh copy.
5. Remove a registered partial installation. Do this only if Microsoft Flight Simulator X appears in Installed apps or Programs and Features after the failed attempt. Uninstall that entry, restart, and use our complete FSX removal procedure if setup still detects an old installation.
6. Test a fresh local administrator profile. Legacy InstallShield releases can fail when the Windows profile’s temporary-folder permissions are damaged or its path contains characters the installer cannot parse. Create a local administrator account with a short Latin-letter name and run setup there. If that works, the fault belongs to the original profile rather than the DVD.

What if error 1607 still appears?

The remaining symptoms usually identify the fault:

• Access denied while renaming the Driver folder: security software or damaged permissions are blocking writes under Common Files. Do not grant the entire Program Files tree full control to everyone.
• The DVD cannot be copied: clean the disc and test another optical drive. Repeated read errors indicate damaged media.
• Other MSI-based installers also fail: repair Windows system files. On Windows 10 or 11, run DISM /Online /Cleanup-Image /RestoreHealth and then sfc /scannow from an administrator Command Prompt.
• Only an add-on produces 1607: the add-on’s installer is the problem. Confirm that it supports the installed FSX edition and run its installer locally as administrator.

Avoid downloading stray isscript.msi packages or individual InstallShield DLL files. InstallScript runtimes are version-dependent, and an unrelated package can replace the original error with a registration or side-by-side failure.

What should I do after FSX installs?

Launch the base simulator once before adding aircraft, scenery or patches. Boxed Standard and Deluxe, Gold with Acceleration, and Steam Edition have different update paths; follow the correct FSX service-pack sequence for your edition rather than installing every patch you find.

If setup gets past error 1607 but then reports an MSXML problem, InstallShield is working and you have reached a separate prerequisite failure. Use the MSXML 4 prerequisite repair steps for that message.