Not sure of any direct built-in way to enable the old-style search on Windows 7. However I did spot something called FileSearchEx which may be in the right direction:
FileSearchEX is for persons who want
extremely fast no-nonsense file
searching capabilities offered from a
clean and intuitive application
interface. In addition to the current
offering advanced features are planned
that will not interfere with design
- Users don't need to learn a new file search utility. XP style search.
- Much lower system requirements than indexing search offerings.
- Support for millions of found items for advanced scenarios.
- Unicode support with internationalized installs planned.
- Large environment easy installation options.
I checked the site and it looks like it's free for personal use.
There's another rather more functional application from NirSoft called SearchMyFiles which provides a lot of options to search for your files and folders.
SearchMyFiles is an alternative to the
standard "Search For Files And
Folders" module of Windows. It allows
you to easily search files in your
system by wildcard, by last
modified/created/last accessed time,
by file attributes, by file content
(text or binary search), and by the
file size. SearchMyFiles allows you to
make a very accurate search that
cannot be done with Windows search.
For Example: You can search all files
created in the last 10 minutes with
size between 500 and 700 bytes.