In Windows Explorer for WinXP there are some differences between WinXP Pro and WinXP Home with respect to the layout and location of the Search and Tools utilities. Menus and options may vary some.

When you select Search there are choices for the kind of things you want to search for, so that you can accept Microsoft's contention that you're an idiot and don't know what's a picture, video, or music file unless they "help" you. Unless you have a particular reason for using one of the other options, I suggest always using the "all files and folders" option. With that option, there should be a place to put in what you want to search for, either all or part of the filename or something in the file.

There should be options to search by file size or by when the file was accessed/modified, and an "Advanced" button/arrow that rolls down some additional options, with (at least in my WinXP Pro) a place there to tell it whether to include hidden and system files, and whether to search in subfolders.

If you choose the option there to include hidden and system files, they usually (probably always) will be found and displayed in the search results regardless of whether you've used the "Tools" options to display them; but I suggest turning on the views in Tools if that's what you're looking for as the display of results may have some "mildly confusing effects" if they're not turned on before you search.

If you know the filename that you want to look for, and really want to be sure¹ if it's there or not, I'd suggest using the "Command Prompt" window (also called, not too accurately, the "DOS Window") and search using both the "DIR" and "ATTRIB" commands, each in turn, from the C:\> folder. (Don't forget the "/S" switch in both.)

Re browsers: Internet Explorer also is "Mozilla Based," although I'm not sure why that's of much significance where it was mentioned(?).

¹ "sure" = "as sure as you can reasonably be"

John