How I Convert Microsoft Excel xlsx Files To Xls Format of Excel 2003 at

When I purchased my Samsung Solar netbook, I uninstalled the trial Microsoft office that came with it and installed the full version of Office 2003 onto the netbook. Last week Monday, a friend sent me an Excel document ending with .xlsx extension. It failed to open on my netbook, telling me “the file is not in a recognizable format“. Instantly I googled for the cause and solution and I decided to share my findings with you today.

As a fact, if you installed Microsoft Excel 2003 on your PC, you will not be able to open a Microsoft Excel file created with Microsoft Office 2007. Excel documents created with Office 2003 ends with .xls while those created with Office 2007 ends with .xlsx.

If you would like to open, edit, and save workbooks that were created in the newer versions Excel with Excel 2003, you either install Microsoft compatibility pack or use a free online document conversion service.

In this post, I am sharing with you how to use Zamzar, a free online file converter which I use to convert .xlsx files to .xls files.


==> Go to on your PC

==> Use the “Browse” button to select the file you want to convert

==> Choose the format you want to convert to. In this instance, you choose “xls” as seen in the picture below:

zamzar online converter

==> Enter your email address and click convert.

==> After some minutes, check your email inbox and you should receive an email from

==> Click the download link in the email to download the converted file.

You should now be able to open the file with your Microsoft Excel 2003.

That’s all.

I hope it helps.

In my future posts,I will share with you how to install the Microsoft compatability pack, so you can  be opening .xlsx files with your Excel 2003 without converting the documents online. Just SUBSCRIBE to my blog for you not to miss this.


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Written by Jide Ogunsanya

Pro Nigerian Blogger, Digital Marketer and Web designer. I help business owners to grow their businesses online. You can join my Facebook Group here or join my Telegram Group here.

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  1. Thanks alot for this. Quite useful to someone like me who don't have access to install any software on the office PC. Now, I no longer have to be sending those .xlsx files to my friend who do help me in converting them. Thanks once again Mr Jide

  2. Good link for converting excel files but why not install office 2010 and save yourself the hassle of all these wahala. lol
    Nigerians too like old software with some still enjoying windows xp launched in 2002! lol
    My samsung solar is currently running windows 8 cp and office 2010 sp1 and it is very fast.

    • You cant be using your PC everywhere you go and there might be instances you are not even a PC that belongs to you. Hence, this trick will come handy at such times. As for the XP, it's not only in Nigeria bro. Many people all over the world still feel more comfortable with it that the newer versions. Your Samsung netbook is running faster because you have 2BG RAM on it instead of the 1GB that comes with it. download Free BBM Animated Avatars

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