Cannot access System Properties (Windows 7)

Question

In Windows 7, I cannot open

• Advanced system settings (nor "systempropertiesadvanced.exe")
• Computer name, domain and workgroup settings (nor "systempropertiescomputername.exe"
• Performance settings (nor "systempropertiesperformance.exe")

I can open System Properties (the page with the basic information about the system), but that's where the buck stops.

The combined effect is critical:

• I cannot manipulate pagefile properties (except from the registry)
• I cannot set theme engine global performance options (except from the registry)
• I cannot set prioritisation between foreground and background (except from registry)
• I cannot change computer name, FQDN, Windows workgroup, etc.

EDIT

Here's some filtered output from Sysinternals' procmon (API logger/profiler)

23:39:24,4178334    DllHost.exe                     3248    CreateFile  C:\Windows\System32\DllHost.exe.Local                       NAME NOT FOUND  Desired Access: Read Attributes, Disposition: Open, Options: Open For Backup, Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a
23:39:24,5730910    DllHost.exe                     4736    CreateFile  C:\Windows\System32\DllHost.exe.Local                       NAME NOT FOUND  Desired Access: Read Attributes, Disposition: Open, Options: Open For Backup, Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a
23:39:24,6609090    systempropertiesadvanced.exe    816     CreateFile  C:\Windows\System32\systempropertiesadvanced.exe.Local      NAME NOT FOUND  Desired Access: Read Attributes, Disposition: Open, Options: Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a
23:39:30,3618838    DllHost.exe                     5756    CreateFile  C:\Windows\System32\DllHost.exe.Local                       NAME NOT FOUND  Desired Access: Read Attributes, Disposition: Open, Options: Open For Backup, Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a
23:39:30,4175383    DllHost.exe                     5916    CreateFile  C:\Windows\System32\DllHost.exe.Local                       NAME NOT FOUND  Desired Access: Read Attributes, Disposition: Open, Options: Open For Backup, Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a
23:39:30,4369174    SystemPropertiesComputerName.exe5960    CreateFile  C:\Windows\System32\SystemPropertiesComputerName.exe.Local  NAME NOT FOUND  Desired Access: Read Attributes, Disposition: Open, Options: Open Reparse Point, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a