On the heels of the Windows 7 Release Candidate public download going live, Microsoft has released a hotfix designed to fix the RC bits. The Redmond company has acknowledged the existence of an issue where incorrect access control lists (ACLs) are associated with the Windows 7 root. As a direct consequence of this bug, Windows 7 RC users will find that some applications fail to perform under normal parameters, and that the operating system fails to deliver on simple tasks. According to Microsoft, only the Ultimate SKU of the English version of 32-bit Windows 7 is affected by the problem.

“The folder that is created as the root folder of the system drive (%SystemDrive%) is missing entries in its security descriptor. One effect of this problem is that standard users such as non-administrators cannot perform all operations to subfolders that are created directly under the root. Therefore, applications that reference folders under the root may not install successfully or may not uninstall successfully. Additionally, operations or applications that reference these folders may fail,” Microsoft explained.

The software giant did not point to any other Windows 7 RC editions as being affected, or to the 64-bit flavor of Build 7100. It is just in the English version of Windows 7 Release Candidate 32-bit Ultimate that users can come across incorrectly set access control lists (ACLs) on the root. The Redmond company has released a hotfix addressing the problem, but users will need to get it straight from Microsoft.

“If a folder is created under the root of the system drive from an elevated command prompt, this folder will not correctly inherit permissions from the root of the drive. Therefore, some specific operations, such as deleting the folder, will fail when they are performed from a non-elevated command prompt. Additionally, the following error message appears when the operation fails: Access is denied. Furthermore, the missing security descriptor entries protect non-admin file operations directly under the root,” the software giant added.

32-bit and 64-bit Windows 7 (Release Candidate) RC Build 7100.0.090421-1700 is available for download here.