Thank you for your post.
The Windows Search Service does not interfere with FileMaker Pro. Although a number of people have reported problems exporting to Excel, I have not incurred any problems when executing Save Records as Excel on Windows XP (sp3). Although disabling any real-time antivirus software has helped many users, it is not a cure-all.
Since this has worked for you previously, something has changed. The trick is to find out what has changed.
Let's start with some basics... Let's assume FileMaker Pro and/or one of its associated files has become corrupt. Uninstalling and reinstalling FileMaker Pro will put new copies of each file onto the hard disk.
If this doesn't fix the problem, then run "msconfig", click on the Services tab, and disable all non-Microsoft Services. This is as basic as you can get.
Please let me know of your progress.