Modify group policy to gain/restrict access rights for windows account

As I started to work, I loaned a laptop from company. It works fine and it is more advanced than my own, however, it is really annoying to find that certain functionality are restricted to access, although I gained the administrator role, those functions were disabled before they loaned it to me, one of which is that I cant access screen saver tab in desktop properties, while by default it is set to start every 5 mins and be password protected on resume, which is quite inconvenience for me as I dont want to input the long password every time I come back to my laptop.

Later I found that I can enabled the tab in group policy, so I tried. Type gpedit.msc from Run, and go to display directory as shown below:
(User Configuration-Administrative Templates-Control Panel-Display)


In the right panel, you can see a list of functionality you can configure, e.g, hide the screensaver tab, etc, by default, the state is "not configured", if you find that the state is same as default, this means that they control the setting from the registry, not thou group policy. In this case, we have to go to registry and delete/modify corresponding registries. Details are as followings:
Delete "ScreenSaverIsSecure" from:

HKEY-Current User\Software\Policies\Microsoft\Windows\Control Panel\Desktop HKEY-Local Machine\Software\Policies\Microsoft\Windows\Control Panel\Desktop

Clean Up Oracle

It is the first time I use Oracle for my work, and the version is 9i.
However, there was a problem for my first time installation, so I just uninstalled the program and tried to reinstall it, and the problem came.
Because I didnt drop existing databases first before uninstalling Oracle, when I reinstalled it and tried to create global database and SID, an error saying that "SID already exists..", as there are so many services running in windows after Oracle had been installed, even it was removed later, the services were somehow still running in the back-end, and there were some files in the directory that could not be removed!
To totally clean up previous install, there are certain things to do and the most important is to remove the registry entries for corresponding services, including:

HKEY_LOCAL_MACHINE/SOFTWARE/ORACLE
HKEY_LOCAL_MACHINE/SYSTEM
----Controlset001/services/%oracle_services%
----Controlset002/services/%oracle_services%

HKEY_LOCAL_MACHINE/SYSTEM/
----Controlset001/ENUM/Root/Legacy%Oracle_services%
----Controlset002/ENUM/Root/Legacy%Oracle_services%

Note that to delete the entries in ENUM under SYSTEM directory, we need log into the system as administrator so that to get the permission.