[Blast]

Попробуйте применить этот твик реестра:

Код:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\.htc]
"Content Type"="text/x-component"
@="htcfile"

[HKEY_CLASSES_ROOT\MIME\Database\Content Type\text/x-component]
"CLSID"="{3050f4f8-98b5-11cf-bb82-00aa00bdce0b}"
"Extension"=".htc"

[HKEY_CLASSES_ROOT\CLSID\{3050f4f8-98b5-11cf-bb82-00aa00bdce0b}]
@="Microsoft Html Component"

[HKEY_CLASSES_ROOT\CLSID\{3050f4f8-98b5-11cf-bb82-00aa00bdce0b}\InProcServer32]
@="C:\\WINDOWS\\System32\\mshtml.dll"
"ThreadingModel"="Apartment"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\CLSID]
"Content Type"="text/x-component"
@="htcfile"

готовый reg-файл