While doing a Find & Replace, Word 2013 does not always highlight the found word

This may be a display driver issue. Check for an updated display driver for your system.

I have downloaded and installed the latest drivers with unfortunately no improvement.

The problem remains.

Just out of interest, have you tried this yourself?

Try searching for something like 'self' but do not specify whole word.

I could not replicate the problem searching for things like "old" in bold or Bold

I promise you, it really is happening. I've checked and it happens with whole words (like bold in your example) and partial words (like old in your example).

Any suggestions?

I am running Office 365 (2013) 32bit on Windows 7 Pro 64bit (all updates and patches applied).

I've checked this in Safe mode and the problem persists.

I've checked that all my drivers are updated.

I just started using Office 2013 about a month ago and I have this issue and find it very annoying.  It is like the scroll bar auto hide.  I do not like having to click the document to make things appear.  Noting that the original post was nearly a year ago, it is disappointing that this is still occurring.  Note:  I installed all updates after installing Office 2013, so clearly no patch on this issue.  =(  

The autohiding of scrollbars is a design change, so it's a different situation.

Have you tried updating the display driver, as Paul/macropod suggested in his reply? 

Windows determined that the driver is up to date.  

This is on my work computer--I spend 95% of my work day on it and probably 95% of that time in Office.  I will have to compare it to my home computer (on which I use Word far less (maybe 1% of my time), but it is easier for my to mess around with display drivers if I find it occurs there).

You could go directly to the manufacturer's web site, which is sometimes necessary to ensure that you find the appropriate updated drivers.