So, in order to remove these entries, do manually according to below steps. But always back up a copy in case something goes wrong.
* Click Start -> Run and type regedit.exe
* Scroll until you find the following key:
HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Uninstall
Note: Here you will see many sub entries, ad each sub entries/subkey represents a program that you've installed. To find out which program that each key represents, click the key, and look at the value of "DisplayName" in the right panel
* Select the right subkey & right-click on the subkey, choose Delete
* Repeat the process until you have finish
* Close Registry Editor
If still there are some programs unable to clean, there are some tools can help to do so, just googling with keywords like "windows installer clean up" or so..