Why does microsoft word 2010 take so long to open?

Check with application safe.

Press ‘Windows key + R’ and in the window type the below one by one and check with the applications.

1.       winword /safe

2.       excel /safe

3.       powerpnt /safe

If you have no issues opening them, the issue might be due to add-ins.

Word

1. Click the Microsoft Office Button , click Word Options, and then click Add-Ins.
2. View the add-ins and application extensions that are categorized as follows:
• Active Application Add-ins     Lists the extensions that are registered and currently running in your Office program.
• Inactive Application Add-ins     Lists the add-ins that are present on your computer but are not currently loaded. For example, smart tags or XML Schemas are active only when the document that references them is open. Another example is the COM add-ins that are listed in the COM Add-ins dialog box. If the check box for a COM add-in is selected, the add-in is active. If the check box for a COM add-in is cleared, the add-in is inactive. To learn how to open the COM Add-in dialog box, see the section calledTurn off or manage the installed add-ins.
• Document Related Add-ins     Lists template files that are referenced by currently open documents.
• Disabled Application Add-ins     Lists add-ins that were automatically disabled because they are causing Office programs to crash.