Even the search capabilities of XP are horrible and unfortunately it has been carried over in Vista and W7. One of the better solutions I have found for your problem and which also works in Vista and W7 is comething called Agent Ransack. ( http://www.mythicsoft.com/agentransack/ ) It is a free file search utility. I have used it for 2 years and it does exactly what MS removed when XP came out. I posted the following about this in the W7 forums with any useful reply.
Hope that will help you out.
From my Win7 forum post.
I am running the RC version of Windows 7 and have unfortunately found no solution to the problems which started in XP and apparently have made their way into W7, at least I have not been able to find it.
Prior to XP one was able to search for text in ANY file type in any directory. For some, as yet unexplained reason the search functionality in XP was arbitrarily limited to include only known document types such as doc, xls, html etc. There was a convoluted "solution" posted on MS's website to circumvent this major issue but even it did not work as advertised. Luckily there were some people annoyed enough by this hi-handed change who took it upon themselves to develop something to do just that. FindinFiles and Agent Ransack come to mind.
What is it about MS that makes them ignore the requests from MANY users over the years for a return of this feature. Do people constantly have to develop new mousetraps for every MS OS because MS figures we do not deserve these features?
I develop software and if I want to look for text inside files in a directory or on an entire hard drive, regardless of file extension, then that should be MY prerogative and I should be able to do so. It should be a basic functionality of ANY OS. Please give us that functionality back in W7