At first to get working the installer, I set the next registry values:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ProductOptions\ProductSuite from "Terminal Server" to empty value and ProductOptions from "ServerNT" to "WinNT" (the same as in XP);
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ReactOS\Settings\Version\ReportAsWorkstation from "0" to "1".
Next I install the File System Filter Manager Driver (fltmgr) from Windows Server 2003 SP2 iso:
- Extract fltmgr.sys from \I386\FLTMGR.SY_ to %SystemRoot%\system32\drivers and fltmgr.inf from \I386\FLTMGR.IN_ to %SystemRoot%\inf by any archiver.
- Go to the %SystemRoot%\inf folder, right click on fltmgr.inf and left click on "Install" for adding a needed values to the registry.
- Run Regedit, go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\fltmgr and set Start from "0" to "1".
After these steps the fltmgr driver works correctly and Avast installation is possible.
But the antivirus can't install correctly anyway. At the finish of setup the installer causes BSOD and after the force reboot the system can't load the boot drivers installed by Avast (see screenshots), although the system boots succesfully. It is reproducible only if install the program in normal boot mode.
If install it in debug mode, at the finish of setup the system hangs(see debug_installation.log), and after the force reboot, the system can't boot at all (after_reboot screenshot). Appears an critical VM error and a VM is becoming non-usable (VBox.log). Helps only restoring a VM from a snapshot to the previous state or making a clear ReactOS installation.