Thanks but there's no need to tinker with the registry.
I found a solution by mhill64 on this link:https://discussions.apple.com/thread/2647111?start=30&tstart=0
QUOTE:
Re: iTunes 10.1 Missing Text
17-Nov-2010 02:35 (in response to wlwbishop)
SUCCESS!!!
The above posts were enough to give me a clue. I have another Win7 x64 machine, and I compared the installed Segoe UI fonts on both systems. Sure enough, there were 6 fonts installed on the 2nd machine, and only 4 on the one with the issue. I was missing Segoe UI (regular), and Segoe UI Bold.
I copied the .ttf files from one machine to the other and right clicked on them and selected 'install'. Fired up iTunes and all text restored.
I also found that I have only 2 types of Segoe UI fonts (there should be 6 all in total). I copied the missing 4 fonts from another Windows 7 computer, and installed them on the problem computer. I opened iTunes and success! Everything is back to normal and the search box problem is fixed too!
Make sure you have these fonts installed: Segoe UI Bold, Segoe UI Bold Italic, Segoe UI Italic, Segoe UI Light, Segoe UI Regular and Segoe UI Semibold.