My scanner is plugged in but when I try to scan a document it says my scanner is not responding

I'm a 99% sure that you've got some hardware problem with your scanner, probably some internal sensor it has is failing. Just as a test, you should install this scanner on another computer - ask a friend for help - test it and if failure persists you have two options: Live with the failure until it goes worst and stops scanning at all or you take it now to repair.
On the other hand, if it works ok on another computer, try to uninstall it completely and reinstall it.

Can you take a screen shot?
or
Try uninstall and re-install the scanner on your Mac

Down load the software for your windows 32 or 64 bit here:

http://h10025.www1.hp.com/ewfrf/wc/softwareCategory?lc=en&dlc=en&cc=us&lang=en&product=1138373&

You need the full package to use the scanner.

To scan a picture or document, follow these steps: Step one: Load the item to scan You can scan from the scanner glass or from the ADF (Automatic Document Feeder) tray, if your product has one.

1. Make sure that the product is connected to the computer.
2. Turn the product on.
3. Load the picture or document:
   • Scanner glass : Place the item with the print side down on the scanner glass, and then position it according to the engraved guides around the glass (usually on the right-front corner or the left-front corner). Close the scanner lid.
   • ADF : Place the item into the document feeder tray. The printed side faces up and the top edge goes into the tray first. Adjust the width guides to fit the item. CAUTION: Do not load photos in the ADF. Use the scanner glass instead to prevent damage to photos.

Step two: Scan the item

1. Open HP Solution Center with one of the following methods:
   • Click Start , click All Programs , click the HP folder, and then click HP Solution Center
   • Double-click the HP Solution Center icon ( ) on your desktop.
2. If you have more than one HP device installed, click the tab or icon for the product that you are using to scan.
3. Use one of the following methods to start the scan:
   • For photos or artwork : Click the on-screen Scan Picture "button" in HP Solution Center.
   • For a text document with or without graphics : Click the on-screen Scan Document "button" in HP Solution Center.
   A screen displays to prompt for scan settings. If a settings screen does not display before the scan starts, a preference was set to bypass the prompt. To adjust settings, follow these steps to turn the prompt back on:
   1. Cancel the scan, return to the home screen of HP Solution Center, and then click the Settings option.
   2. For the HP Solution Center "button" that you are using ("Scan Picture" or "Scan Document"), set the option to prompt for settings each time you scan, and then click OK .
   3. Start the scan again.
4. Read through the various options for the scan settings. Make selections for at least the following items:
   • Scan to: Select your scan destination from the drop-down list.
   • File Type: Select the file type from the drop-down list.
   • ...Save Options...: (available only for certain "Scan to" destinations): For example, if you are saving to a file, click this option to select your Save Location .
   • Show preview...: Select this check box if you want to see a preview before the actual scan.
   Important : HP Solution Center software versions vary, depending on the age of your product, and whether you installed updated software after the initial setup. For specific instructions on all the settings the software offers, click the Help button on the home screen or settings screens in HP Solution Center.
5. Click Scan . The preview screen might display, if you selected an option to show a preview. Use the options on the preview screen to make any desired adjustments before you complete the scan.

After the scan completes, it goes to the destination that you specified in the settings. Using the scan button on your printer HP recommends that you first get comfortable with using the "Scan Picture" and "Scan Document" on-screen "buttons" in HP Solution Center as explained in the previous steps. By doing this, you determine the scan settings that you use most often, and then you can more easily set up the scan button on your printer. Important: Before you use the scan button on your printer, use HP Solution Center to create the settings for that button . For example, you need to decide whether you want a settings prompt screen and a scan preview for each scan. Also, you must create the list of "shortcuts" that you want to display on the front panel of the printer. To get started, click Settings , click Scan Settings , click Button Settings , and then click the tab for Front Panel Scan Buttons . Read through the options, and then create the settings that you want.

Double Click on HP Solution Center icon to open. The HP icon will be on your desktop or in your start menu. It is the icon that materializes after you use the CD to install your HP scanner or multifunction printer. (It may appear slightly different depending on the model and type of HP scanner or printer).
Place the document or photo on the glass platen in the proper corner. There is an arrow that illustrates proper placement in HP scanners and printers.
Click the settings button on the bottom of the HP Solution center screen. It appears as a wrench. This will assist in setting up your scanner or all-in-one HP printer to scan at the touch of a button. Follow the on-screen prompts for photos and documents. Then, scan by clicking the Scan Picture or Scan Document button as appropriate.
Select the proper choice once you scan, such as save to file (specify where) or email (You also can set up a folder ahead of time so you know where to find the document or photos once they are scanned). Often times the computer will create a default my scans folder and organize them by saving them by date and month scan.
Click scan and then wait for box to appear. You will see the document or photo being saved and the blue bar will display progress in the HP screen.
Save the file if the HP software has not already done this for you. Put it in a folder you create and give it a name you will remember.
Then click "Save"to finalize it. The document should be in the folder that you designated.
Repeat the process for multiple pages. Keep the HP Solution Center screen open until your scans are finished.

make sure that scan driver is completely installed in your computer.

To scan a documents in jpeg format, use the scanner icon in the control panel of your system. Insert your document in scanner bed then double click the scanners & cameras icon in the Control Panel.

To scan a documents and save in pdf format. just press the Scan button in the printer and save the documents in your computer once the scan window appear.

hello ! reinstall the machine fax and scanner program cd's may be the installation was not completed or is the machine having issues .

Have you tried pressing the scan button on the printer, what happens?

What about the Scanner and Camera Wizard,
go into my computer and double click on the scanner icon then follow the prompts

more info here

just try once by reloading the drivers and try with another usb port and cable, if the problem is not solved then your scanner needs servicing

My printer does the same. And it's my third Canon printer and ever time when I try to scan a picture or etc. it just ends up saying that the printer can't communicate or that it's shut off. :(

No scan options
Refer to device documentation to troubleshoot.