Another instance of application is already running.

[Gear_Grinder]

Just installed HP Print & Scan Doctor. When I try to run it I get the message "Another instance of application is already running." Trying to correct.

[Nal_NR]

Hi @Gear_Grinder,

Welcome to the HP Support Community. 

I'd be glad to help you! 

I’m sorry to hear about the trouble running the HP Print & Scan Doctor—it’s frustrating when a tool meant to solve problems won’t cooperate. Let’s work through this together.

• Did you previously attempt to open HP Print & Scan Doctor and close it, or did the system crash during a prior session?
• Have you tried restarting your computer and checking for any background processes related to HP Print & Scan Doctor?
• Are there any other HP software or utilities running at the same time?

Check Task Manager for Active Processes

• Press Ctrl + Shift + Esc to open Task Manager.
• Look for any process named HP Print & Scan Doctor, or similar HP-related processes.
• Right-click the process and select End Task, then try running the tool again.

Restart Your Computer

• Restart your system to ensure all previous instances of the tool are fully closed. After the reboot, open HP Print & Scan Doctor directly without launching other HP utilities.

Reinstall HP Print & Scan Doctor

• Uninstall the current version of HP Print & Scan Doctor.
• Download the latest version from the official HP support website and reinstall it.

Check for Conflicting Software

• Ensure no other printer management tools or utilities are running that might conflict with the HP Print & Scan Doctor.
• Temporarily disable antivirus software, as it could block the tool from running.

Run the Tool as Administrator

• Right-click on the HP Print & Scan Doctor shortcut and select Run as administrator.
• This ensures the tool has sufficient permissions to operate correctly.

You may also refer to this document for more information. 

Hope this helps! Keep me posted for further assistance

Please mark this post as “Accepted Solution” if the issue is resolved and if you feel this reply was helpful click “Yes”.

[Gear_Grinder]

Thanks Elohi_NR,

I fear I did not define my problem well &/or I do not understand the printer options.

I had a Windows 10 computer that died. On that machine I had a desktop shortcut I used to manage scanning from the computer rather than from the printer. This scan control would let you select the format & then where you wanted the scan saved. I am not certain, but I do not think this the Print &Scan "Doctor".

I now have the same printer connected to a different Windows !0 computer. I do not know if it is causing a conflict, but the new computer previously had an HP 3510 printer installed. Hoping to install the shortcut to this same functioning. I can print from the new computer. Sure would like to find the slick way I had to do scans.

Thanks

[Nal_NR]

Hi @Gear_Grinder,

Thank you for performing the recommended steps, I see that it has not helped.

It sounds like you previously used HP Scan software (part of the HP full feature driver package) on your old Windows 10 computer to manage scanning directly from your computer, rather than initiating it from the printer's control panel. This program allows you to choose formats (e.g., PDF, JPEG) and specify where to save scanned documents.

Let’s walk through restoring that same functionality on your new Windows 10 computer:

1. Install the HP Full Feature Software and Drivers

• Go to the HP Support website: https://support.hp.com/
• Search for your printer model (e.g., HP OfficeJet Pro 6978 or your specific printer).
• Under Driver-Product Installation Software, download the HP Full Feature Software for Windows 10.
• Run the installer and follow the on-screen prompts. This installation should include the HP Scan software.

2. HP Scan Setup

Once installed:

• Search for HP Scan in your Start Menu.
• Open HP Scan. This tool allows you to:
  • Select scan options (color, resolution, format like PDF/JPEG).
  • Choose the folder where you want the scanned files saved.
• If you use this frequently, you can create a shortcut:
  • Right-click the HP Scan app in the Start Menu.
  • Select More > Open File Location.
  • Right-click the app again and choose Send to > Desktop (Create Shortcut).

3. Remove Old Printer Drivers to Avoid Conflicts

Since your previous computer used an HP 3510 printer, old drivers might cause conflicts:

• Go to Control Panel > Programs and Features.
• Look for any software related to the HP 3510 and uninstall it.
• Open Devices and Printers.
• If you see the HP 3510 listed, right-click and choose Remove Device.
• Restart your computer.

4. Test the Shortcut

• Double-click your new HP Scan shortcut on the Desktop.
• Test a scan to ensure you can select the format and destination folder.

Keep me posted for further assistance

Please mark this post as “Accepted Solution” if the issue is resolved and if you feel this reply was helpful click “Yes”.