How do I know what registry keys should be removed?

I am writing a Java Desktop Application and one of it's functions is going to remove old un-needed, useless Registry entries. How do I determine what entries/keys/values can be removed.

After Looking At The Registry

• I installed and then uninstalled my application and I noticed that the key for my program in HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall was still there but the values were removed.
• Although the key was still there, the program was no longer in the Uninstall Programs list and the program was uninstalled.
• I then looked around and found that there are other keys in that location that do not have any values.

Are Keys wi开发者_如何学Cth no Sub-keys or Values old? Would these be safe to remove?

• I also found that some of the Keys in that location do not have an InstallDate value. All the programs/updates in Uninstall Programs have an Install Date.

What should be my policy when deciding whether or not to remove a registry entry and what should I keep in mind?

Most of uninstall programms find Value "UninstallString", and if that mission failed, it's don't show results. At my program i deleted program, values at "\Uninstall", and key too. I think, that it is safety.