My suggestion to use asterisks around the term, like
*160.99*, worked for the poster,
and below is my reasoning.
Character based versus word based search, or Searching with wildcards on Windows Vista
On Windows XP search is character based. That is, if you search for a
string 'test', it will find files named 'my test data.doc',
'additional testing.xls' as well as 'latest junk.txt' or (if you tell
it to search also contents of files) files containing words such as
'test', 'tester' and 'fattest'.
On Windows Vista, and on Windows XP with WDS installed, search is
normally word based. Searching for the string 'test' will only find
documents with the word 'test' in them, or words beginning with
'test'. So it will find the files named 'my test data.doc' and
'additional testing.xls' but it will not find 'latest junk.txt'.
Moreover, it will find documents containing 'test' or 'tester' but it
will not find documents containing 'fattest'.
The main reason for the change is that by making search word based one
can use an index to make searches much faster.
My reasoning was that because of the point in the file-name, the Windows algorithm
for extracting words has failed. The asterisks were added as an attempt to force
a search that is more character-based, which did work.
That said, I do counsel against using Windows Search, by reason of its simply being
too flaky and just too weird.
Disabling it is one of the first changes that I do with a new computer.
Here are two products that are much better at searching file-names :
Everything Search Engine : Uses an index and is lightning-fast.
FileLocator Lite : Does not use an index, so starts faster but searches slower.
I consider the Everything Search Engine as one of my most useful utilities,
and set it up to start with Windows so it will always be up to date.