Find A File Without Knowing Where It Is On All Drives?

SPECS: Visual Basic 2008 - SP1/2, Framework 3.0.3.5, Windows XP Pro, SP3? trying to wright code for checking for existing files but what has me stumped is the (WHAT IF PART) of it witch in fact is what I want to see. What im saying is can I find a file without knowing where it is on all drives? Or how can i find a folder if I dont know where they installed it to.

Example: I know that C:Perfect World International <--- is the default location where my game installs but what if I installed it on D:Perfect World International; or rather on drive G or H. How would I test to see if it exist without making a bunch of nested If statements to test every drive for it.

this also applies to files like: D:Perfect World EntertainmentPerfect World Internationalelementelementclient.exe is there a way to find these files to see if they exist. I know that Perfect world international does not use the program files to put there program files in as you see above. so Envirnment variables I think cant be used correct me if I'm wrong. BUT I know the registry of a computer keeps some stord information as to where these applications are installed to like (References App Data).

What I'm trying to do is use this to tell the user in a Label that the game is installed in this path but I know in some circumstances the game is not installed on drive C: or D: or even in this directory some users can install it in there own directory such as C:PWI. and as such the file elementclient.exe can even be in C:PWIelementclient.exe. So to sum it all up can this be found useing some sort of code to find the file and folder and return them both in 2 difrent labels like this

Game Is Installed In: C:Perfect World International
Game Client Name: elementclient.exe, C:Perfect World Internationalelement
Game Found On Drive: C:
ETC.

I'm thinking and keep thinking that this can be done in many ways but as for environment variables I'm stumped. But perhaps windows registry may play a role in doing this but I myself don't even know where this stuff may be found; and even more how to apply it to code.