Today, I have to install Netbeans 5.5, a very popular IDE for Java, on my friend's notebook. At first, the installer said that there is no JDK on this computer. So we find another Netbeans installer pack which included JDK 6. But the situation is almost the same. The installer asked to locate the "java.exe" file but after I select the correct file it said file is corrupted.
We try restarting Windows, reinstalling the JDK, but none of them worked. After a while, I noticed that my friend's Windows user name is a little weird (It contain "@" and "!"). So I try create a new Windows user account. And try install Netbeans again from there. Bang! It worked!
I realized that this is not the first time I experienced this problem. So, do not name your next Windows account with those weird characters :)