Opening excel file directly is very slow

I tried both enabling Superfetch and changing the registry as proposed above but not solved the problem.

Then I right clicked an xlsx file->Open With, selected as default the executable in "C:\Program Files\Microsoft Office\Office12\EXCEL.EXE" and now it opens super fast.

This worked for me as well, just changing it to the following worked for office Excel 365.

"C:\Program Files\Microsoft Office 15\Root\Office15\EXCEL.EXE" "%1"

My EnableSuperfetch was already set to 3 and my PC was exhibiting all the same issues pointed out in the initial request.  Great Help for the suggested change to regedit that helped.

I have been studying this problem using the Procmon64 process explorer. I have two desktop systems, side by side, and one has the slow Excel startup, and ones does not. Both machines are Windows 10, and both have SSD drives. The differences are that the slow-opening  machine is newer, faster, has more RAM, was upgraded from installed Windows 8.1 and has Office 365. The fast-opening machine is older, slower, has less ram, was upgraded from installed Windows 7 and has Office Professional 2013. Both use the same Microsoft account for signon, but the fast-opening machine always used that account, and the slow-opening machine was changed from a local account when migrated from Windows 7,

I ran Procmon64 with a filter on the path to show either EXCEL or .XLS contained in the path. I have some things to note:

• The slow-opening machine opens a thousand registry keys and then there is nothing for a second, and then a few activities, and then it freezes for 8-9 more seconds, while the fast-opening machine has no such delays opening roughly the same number of keys.
• I was surprised to see Skype.exe on the slow-opening machine opening registry keys for EXCEL! However, quitting Skype made no difference.
• Both machines use Windows Defender for anti-virus, and shutting down real-time protection made no difference.
• I tried shutting down various processes including iCloud and OneDrive. Didn't make a difference.
• I reinstalled Office Professional 2013 on the fast machine, and it was still fast.
• I created a new local account on the slow machine, and then it was fast, but I don't want to change accounts.
• Both machines have SuperFetch turned on, and it shows in the Procmon64 references.
• Disconnecting from the network made no difference.

I tried booting in safe mode, but Office 365 doesn't appear to run in safe mode.

I tried this also on my Surface 3 Pro, and it was 2-3 times slower than the slow-opening machine, which would be expected because that tablet is slower. I tried it on a Dell Venue 8 Pro and it took about 12 seconds to open a file from Explorer vs. 3 seconds to start Excel by itself.

Hello,

Welcome to Microsoft Community and thank you for posting the question.

From your description I understand that it takes longer time to open an Excel file.

I will assist you to resolve this issue, however I need additional information:

1. Is this issue experienced only on a specific Excel file or on all Excel files?
2. What is the size of the Excel file and where is it saved? It is on local drive or on a network location?
3. What are the contents of the Excel file? Does it contain any complex formulas?
4. Do you experience any similar issues with other Office applications like Word or Excel?

If the issue is a specific file, let’s take a backup of the Excel file and then try repairing it and verify the result.

Check the link below for instructions on how to repair an Excel file.

http://office.microsoft.com/en-gb/excel-help/repairing-a-corrupted-workbook-HA010342840.aspx

I hope the above information helps. Reply with necessary information and the result for further assistance.

Thank You.