When I install some module/plugin to Netbeans it lost in many other Netbeans 
default plugin and when I need uninstall it, I can't found it.

Much better would be more type of view to "Installed plugin" or/and separate 
windows with "History of install"

If you decide for more type of view to "Installed plugin", I suggest this:
- by Catagery (it exist now)
- by Update Center (categorize plugins to update centers groups)
- by installation type:
     - default Nebtenas plugins
     - myself installed plugin
     - maybe differentiate  plugin installed via update center and manual from 
nbm files.
     - maybe diffrerentiate local and global install (it this will be supported 
in Netbeans 6. I hope so.

In list of installed plugin would be also date of install.