[Osiris]

By default Windows XP searches only inside a handful of selected file types and ignores file types that are not registered in Windows. This means for instance that the Windows search is not searching through php documents. Here is a quick Registry hack that enables searching in all file types and not only a selected few.
Open your Registry by pressing Windows R, typing regedit and hitting enter. Navigate to the Registry key HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet\ Control \ContentIndex and double-click the entry FilterFilesWithUnknownExtensions. The default value of this entry is 0 which means that Windows will not search in unknown file extensions.
Set it to 1 to make the search more universal. Changes take effect immediately and Windows will from then on search in all files. This includes php and htm files for example which Windows does not search in by default.