Where is the real MT4 indicators/experts folder?

Recently I installed MT4 build 646 in Windows 7. I installed under "Program files" folder. I copied my EA file to"experts" folder inside "Program files" folder. I failed to compile the EA, it gave me "EX4 write error". I guess that's because creating a file inside "Program files" require Administrator permission. Then I found "AppData". I copied the EA to "AppData" folder and compile it. The problem is that EA didn't show up when I try to run it on Tester.
It seems that tester use "experts" folder inside "Program files" folder as it's directory. Am I correct? How to solve this problem? It seems that I can't compile the EA under "Program Files", on the other hand Tester use EX4 file under original folder, not from "AppData" folder. Should I uninstalled MT4 and reinstalled it to folder outside "Program files" folder?

Also it seems that tester in build 646 is much slower than in previous version, is it?

do not install it inside programs(xxx)-folder. ...

for the folder-structure, pls. see http://www.forexfactory.com/showthread.php?t=470340

Yes, I already reinstalled it. Thanks.

If someone has already installed it inside programs(xxx)-folder. ...
You can try this way to find the folder you want:
File → Open Data Folder → MQL4 → Experts