It is possible that a virus could do that. Remove the virus as soon as possible.
Registry Defender virus is a fake registry cleaner and rogue registry repair application advertised via a trojan horse virus. It can significantly slow down your computer and internet.
The operating system will not allow limited users to change any of the system's settings or applications or add/removing programs or registry. Only Administrators can do all these things. User can only view the data. so the in the user account when user want to access registry he can not access and it shows an error as "Registry editing is Disable by your Administrator" I didn't find the above answer useful. Visit the related link where you will find how to enable or disable registry.
Many times Explorer will remove or disable the Folder Option in Tools but there is a way to deal with it. If Folder Options is disabled but Registry Editor is still working in your system, then you can enable Folder Options by editing Windows Registry.
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You can not do that because virus uses programming to edit in registry. If you are trying to recover registry after virus has edited them then your efforts are worthless because best antivirus Kaspersky too fails to do that. This is because,registry is basically collection of settings which user wants for himself.Due to this reason any antivirus does not interfere with registry.
Housecall is not a virus but an online virus scanner
The Registry Mechanic software offered by PC Tools checks the registry for errors that can slow down and crash the computer and provides people with a full toolbox for finding and repairing your registry.
There are many examples of quality registry tools. These include the likes of CCleaner, Jet Clean, Wise, Auslogics, Advance SystemCare and Registry Repair.
Registry fix is a very good source to solving computer virus problems. Registry fix will scan your computer for viruses; however, like with all viruses, the sooner they are found, the easier registry fix can help you.
Using the Group Policy Editor · Click Start, Run and type gpedit.msc and press ENTER · Go to the following location: User Configuration Administrative Templates System · Double-click Disable registry editing tools and set it to Disable · Minimize the Group Policy Editor for now, and try to launch the Tweak UI, you should be able to launch it now · Go back to the Group Policy Editor, and set the "Disable registry editing tools" back to Not Configured Source: http://geekvalley.blogspot.com/2008/06/tweak-ui-has-been-disabled-by-your.html
The PC Tools website by Symantec offers a free PC Tools Registry Mechanic download. This application is designed to clean one's Windows Registry in one easy step.
no but you can get hacked...