Class not registered, mdac and other problems

[papaja]

Hello,
I believe I didn't change anything on my machine but my web
applications, particularly pages accessing Microsoft Access DB,
suddenly refused to work.

I get this error:

----------------------------------------------------------

Server Error in '/tulumovic' Application.
Class not registered
Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more
information about the error and where it originated in the code.

Exception Details: System.Runtime.InteropServices.COMException: Class
not registered

Source Error:

An unhandled exception was generated during the execution of the
current web request. Information regarding the origin and location of
the exception can be identified using the exception stack trace below.

Stack Trace:

[COMException (0x80040154): Class not registered]
System.Data.Common.UnsafeNativeMethods.CoCreateInstance(Guid rclsid,
IntPtr pUnkOuter, Int32 dwClsContext, Guid riid) +0
System.Data.OleDb.OleDbConnection.CreateInstanceDataLinks() +172
System.Data.OleDb.OleDbConnection.CreateInstanceMDAC() +93

[InvalidOperationException: The .Net Data OLE DB
Provider(System.Data.OleDb) requires Microsoft Data Access
Components(MDAC). Please install Microsoft Data Access
Components(MDAC) version 2.6 or later.]
System.Data.OleDb.OleDbConnection.CreateInstanceMDAC() +127
System.Data.OleDb.OleDbConnection.GetObjectPool() +177

System.Data.OleDb.OleDbConnection.CreateProvider(OleDbConnectionString
constr) +13
System.Data.OleDb.OleDbConnection.Open() +203
tulumovic.kuhinja.najRecept() +77
tulumovic.kuhinja.Page_Init(Object sender, EventArgs e) +56
System.Web.UI.Control.OnInit(EventArgs e) +67
System.Web.UI.Control.InitRecursive(Control namingContainer) +241
System.Web.UI.Page.ProcessRequestMain() +174


Version Information: Microsoft .NET Framework Version:1.1.4322.573;
ASP.NET Version:1.1.4322.573
----------------------------------------------------------

Please note line saying:
[InvalidOperationException: The .Net Data OLE DB
Provider(System.Data.OleDb) requires Microsoft Data Access
Components(MDAC). Please install Microsoft Data Access
Components(MDAC) version 2.6 or later.]

I installed mdac sdk 2.8, but it didn't solve my problem. What else
could I try ?