This form of virtualization is an interim application compatibility technology; Microsoft intends to remove it from future versions of the Windows operating system as more applications are made compatible with Windows Vista and later versions of Windows. Therefore, it is important that your application does not become dependent on the behavior of registry virtualization in the system.
Windows Vista File System Virtualization
Virtualization is intended only to provide compatibility for existing applications. Applications designed for Windows Vista and later versions of Windows should not write to sensitive system areas, nor should they rely on virtualization to remedy any problems. When updating existing code to run on Windows Vista and later versions of Windows, developers should ensure that applications only store data in per-user locations or in computer locations within %alluserprofile% that properly use an access control list (ACL).
Prior to Windows Vista, applications were typically run by administrators. As a result, applications could freely access system files and registry keys. If these applications were run by a standard user, they would fail due to insufficient access rights. Windows Vista and later versions of Windows improve application compatibility for these applications by automatically redirecting these operations. For example, registry operations to the global store (HKEY_LOCAL_MACHINE\Software) are redirected to a per-user location within the user's profile known as the virtual store (HKEY_USERS\_Classes\VirtualStore\Machine\Software).
Note that using the registry as an inter-process communication (IPC) mechanism between a service (or any other process that does not have virtualization enabled) and an application will not work correctly if the key is virtualized. For instance, if an antivirus service updates its signature files based on a value set by an application, the service will never update its signature files because the service reads from the global store but the application writes to the virtual store.
Whenever auditing is enabled on a key that is being virtualized, a new virtualization audit event is generated to indicate that the key is being virtualized (addition to the usual audit events). Administrators can use this information to monitor the status of virtualization on their systems.
This policy setting enables or disables the redirection of the write failures of earlier applications to defined locations in the registry and the file system. This feature mitigates applications that historically ran as administrator and wrote runtime application data to %ProgramFiles%, %Windir%, %Windir%\system32, or HKEY_LOCAL_MACHINE\Software\.
UAC virtualization is a fundamental element of Micorosft\u2019s security strategy for Windows. Turning UAC off loses you the benefit of native security procedures.","author":"@type":"Person","name":"Stephen Cooper","description":"Stephen Cooper has taken a close interest in online security since his thesis on Internet encryption in the early 90s. That formed part of his BSC (Hons) in Computing and Informatics at the University of Plymouth. In those days, encapsulation techniques were just being formulated and Cooper kept an eye on those methodologies as they evolved into the VPN industry. Cooper went on to study an MSC in Advanced Manufacturing Systems and Kingston University.\nCooper worked as a technical consultant, sitting DBA exams and specializing in Oracle Applications. With a long experience as a programmer, Cooper is able to assess systems by breaking into programs and combing through the code. Knowledge of IT development and operations working practices helps him to focus his reviews on the attributes of software that are really important to IT professionals.\nAfter working as an IT consultant across Europe and the USA, he has become adept at explaining complicated technology in everyday terms. He is a people person with an interest in technology\n","url":"https:\/\/www.comparitech.com\/author\/stephen-cooper\/"}},"@type":"Question","name":"How do you make an executable not subject to UAC virtualization?","answerCount":1,"acceptedAnswer":"@type":"Answer","text":"There are two ways that an executable can be exempted from UAC virtualization. The first is to design the software as a portable package that doesn\u2019t need to be installed but will run as a file in the location where it was downloaded. The other way to avoid UAC virtualization kicking in when the program runs. The other way is to include an Application Manifest with its installer. This should contain an entry for requestedExecutionLevel with a value set at asInvoker or highestAvailable.","author":"@type":"Person","name":"Stephen Cooper","description":"Stephen Cooper has taken a close interest in online security since his thesis on Internet encryption in the early 90s. That formed part of his BSC (Hons) in Computing and Informatics at the University of Plymouth. In those days, encapsulation techniques were just being formulated and Cooper kept an eye on those methodologies as they evolved into the VPN industry. Cooper went on to study an MSC in Advanced Manufacturing Systems and Kingston University.\nCooper worked as a technical consultant, sitting DBA exams and specializing in Oracle Applications. With a long experience as a programmer, Cooper is able to assess systems by breaking into programs and combing through the code. Knowledge of IT development and operations working practices helps him to focus his reviews on the attributes of software that are really important to IT professionals.\nAfter working as an IT consultant across Europe and the USA, he has become adept at explaining complicated technology in everyday terms. He is a people person with an interest in technology\n","url":"https:\/\/www.comparitech.com\/author\/stephen-cooper\/"]} "@context":"http:\/\/schema.org","@type":"BreadcrumbList","itemListElement":["@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.comparitech.com\/","@type":"ListItem","position":2,"name":"Net Admin","item":"https:\/\/www.comparitech.com\/net-admin\/","@type":"ListItem","position":3,"name":"What is UAC virtualization?","item":"https:\/\/www.comparitech.com\/net-admin\/uac-virtualization\/"]Net AdminWhat is UAC virtualization? We are funded by our readers and may receive a commission when you buy using links on our site. What is UAC virtualization? What is UAC virtualization and when should it be deployed? We explain it in this topic. Stephen Cooper @VPN_News UPDATED: February 1, 2022 body.single .section.main-content.sidebar-active .col.grid-item.sidebar.span_1_of_3 float: right; body.single .section.main-content.sidebar-active .col.grid-item.content.span_2_of_3 margin-left: 0;
Rather than mediating between two different operating systems, the UAC virtualization provides the services that the software needs to run in a user account without breaking the strict system isolation of UAC. Access to the folders that the software needs is blocked and that fact would cause the program to hang or fall over.
Thanks to the UAC virtualization, software that writes to C:\Program Files\, is really writing to %LOCALAPPDATA%\VirtualStore\. Thus, a mapping interface between folders in the virtualization keeps old software working while protecting reserved system directories.
Not all software is going to need access to protected system areas. Some programs download as executable files and run from wherever they are resident on the computer. The main issue of whether or not a program needs to write files to reserved directories comes down to a matter of the organization of folder access needs.
Registry virtualization is the application of UAC virtualization to the system registry. The purpose of this feature is to block access to global registry entries while enabling software that requires such access to continue to function. As UAC interprets folder access and diverts write actions to user-controlled directories, Registry virtualization switches attempts to write to global variables to safer user account registry keys.
Registry virtualization is only implemented in order to enable legacy systems to continue operating. The need for this service is probably, by now, almost completely defunct. Any software that was written after 2006 will not need the registry virtualization service because it should have been written along with Microsoft developer guidelines. These guidelines explain the difference between global registry entry use and the registry keys that are available to user accounts.
UAC virtualization was created to ensure backward compatibility when Microsoft launched its new architecture. It is a method for preventing legacy software from failing because they are no longer permitted to write to the files whose paths and names are hardcoded.
The other major substitute for UAC virtualization protection is the Controlled folder access system. This prevents malware from changing the extensions on files to hide them or altering system folder names. This can also be accessed from the Virus & threat protection settings screen where you turned on Tamper protection.
In earlier versions of Windows, Applications written with the assumption that the user will be running with administrator privileges experienced problems when run from limited user accounts, often because they attempted to write to machine-wide or system directories (such as Program Files) or registry keys (notably HKLM).[5] UAC attempts to alleviate this using File and Registry Virtualization, which redirects writes (and subsequent reads) to a per-user location within the user's profile. For example, if an application attempts to write to a directory such as "C:\Program Files\appname\settings.ini" to which the user does not have write permission, the write will be redirected to "C:\Users\username\AppData\Local\VirtualStore\Program Files\appname\settings.ini". The redirection feature is only provided for non-elevated 32-bit applications, and only if they do not include a manifest that requests specific privileges.[15] 2ff7e9595c
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