Warren Smith can't preview Word or Excel files in Windows Explorer. He asked the Answer Line forum for help.
The Windows 7 version of Windows Explorer can preview .jpgs, .pdfs, and other popular formats. Select Organize>Layout>Preview pane to see a file's contents.
But it can't always preview .docx, .xls, and other Microsoft Office file formats. I know of three possible reasons.
You don't have Microsoft Office
Explorer needs Microsoft Office installed to read the popular suite's various formats. I'll leave you to guess at Microsoft's motivations for that shortcoming.
The files you're trying to preview are very old
The age of the files could be causing the problem. As a security precaution, Word 2010 won't open .doc files created in a version of Word earlier than 97 (the format was more susceptible to macro viruses, back then). And if Word won't open them, it won't help Windows Explorer preview them, either.
Excel behaves similarly.
Here's how to fix the problem in Word 2010:
Click the File tab (dark blue and immediately to the left of Home). Click Options in the left pane. In the Word Options dialog box, click Trust Center, again in the left pane. Click the Trust Center Settings button. In the Trust Center's left pane, click File Block Settings.
The resulting options may confuse you. If the Open option for a file type is checked, that means you can't open those files. So I recommend unchecking everything.
After you make these changes, be careful about any old files you open--although I suspect that there aren't many pre-1997 viruses floating around that your antivirus program doesn't know about.
The same instructions work for Excel.
You have the wrong edition of Microsoft Office
If you're using Microsoft Office Starter edition (a very limited, advertiser-supported version that comes bundled with some PCs), you won't be able to preview these files. It appears that Office Starter doesn't support Windows Explorer preview, and the only fix is to upgrade to another version.
I say "It appears" because I haven't been able to test it myself, and Microsoft has refused to confirm or deny this shortcoming.
My thanks to ElfBane for bringing up the age issue, and to LiveBrianD for suggesting the Starter problem, both in the original forum discussion.
Contributing Editor Lincoln Spector writes about technology and cinema. Email your tech questions to him at email@example.com, or post them to a community of helpful folks on the PCW Answer Line forum. Follow Lincoln on Twitter, or subscribe to the Answer Line newsletter, e-mailed weekly.