Run a Legacy ActiveX Control in 64-Bit Excel 365
Question details
The user needs to run a legacy ActiveX control in Excel 365 to communicate with a serial pressure-measurement device.
- Product
- Microsoft Excel 365
- Device & OS
- not provided
- Scenario
- A legacy ActiveX component must be registered and used with a serial pressure-measurement device in modern Excel 365.
- Observed behavior
- The control may fail to register or load when Excel 365 is running as a 64-bit application because the control is a 32-bit component or uses outdated registration technology.
Check whether Microsoft Office and the ActiveX control are 32-bit or 64-bit, and confirm the control vendor's registration instructions. Make sure you have administrator permission before registering the component or modifying the Office installation.
Use 32-bit Microsoft Office for the legacy ActiveX control
Use this option when the control vendor confirms that the component is 32-bit and no 64-bit version is available.
A 32-bit ActiveX control generally cannot load inside 64-bit Excel because the two components use different application architectures. Installing the 32-bit edition of Microsoft Office can restore compatibility, provided the control is registered correctly and supported by the vendor.
Open Excel 365, select File > Account > About Excel, and check whether the installation is 32-bit or 64-bit.
Close all Office applications, open Windows Settings > Apps > Installed apps, select Microsoft 365 or Microsoft Office, choose Modify, and install the 32-bit edition if your license and organization policy allow it.
Follow the vendor's registration instructions from an administrator account, then restart Excel and test the ActiveX control from the worksheet or VBA project.
Replace the legacy control with a supported 64-bit interface
Choose this option when the organization must keep 64-bit Office or the original control cannot be registered reliably.
Use WPS Office for compatible spreadsheet and document work
WPS Office is a free, lightweight Microsoft Office alternative for opening, editing, and sharing compatible spreadsheets while you resolve the Excel-specific ActiveX dependency. It provides a familiar interface and supports common Microsoft Office formats, but it does not directly repair or run a legacy Excel ActiveX control tied to a serial device.
Frequently Asked Questions
Why does a 32-bit ActiveX control fail in 64-bit Excel 365?
A 32-bit ActiveX control cannot normally load inside a 64-bit Excel process because the component and host use different architectures. Installing 32-bit Office or obtaining a native 64-bit replacement is usually required.
How can I check whether Excel 365 is 32-bit or 64-bit?
Open Excel and go to File > Account > About Excel. The dialog shows whether the installed Office application is 32-bit or 64-bit.
Will lowering ActiveX security settings fix the registration problem?
No. Security settings can block a permitted control, but they cannot resolve a 32-bit and 64-bit architecture mismatch or outdated registration technology.
Can I install 32-bit Office if 64-bit Office is already installed?
You generally need to modify or uninstall the existing Office installation before changing the bitness, and your Microsoft 365 license or organization policy must permit the change. Check with your administrator before proceeding.
What should I do if the vendor no longer provides a 64-bit ActiveX control?
Ask the vendor about a supported driver, API, modern interface, or hardware replacement. If no supported option exists, keep the required 32-bit Office environment isolated for the device workflow and use a separate current Office installation for other work.
