I have installed windows 7 x64, therefore i have a confusion whether i have to install JDK x64 or JDK x86? please help me, thank you
For the most part 32 bit apps will run fine on 64 bit windows (32 bit drivers are another story).
It is possible that the 32-bit version of Java will run slower than the 64 bit version (possible does not mean it will, just that it could). It is also possible that the 64-bit version will use more memory than the 32 bit version.
Personally I use 64-bit version of things when available.