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.Com mon.UnsafeNativ eMethods.CoCrea teInstance(Guid rclsid,
IntPtr pUnkOuter, Int32 dwClsContext, Guid riid) +0
System.Data.Ole Db.OleDbConnect ion.CreateInsta nceDataLinks() +172
System.Data.Ole Db.OleDbConnect ion.CreateInsta nceMDAC() +93

[InvalidOperatio nException: 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.Ole Db.OleDbConnect ion.CreateInsta nceMDAC() +127
System.Data.Ole Db.OleDbConnect ion.GetObjectPo ol() +177

System.Data.Ole Db.OleDbConnect ion.CreateProvi der(OleDbConnec tionString
constr) +13
System.Data.Ole Db.OleDbConnect ion.Open() +203
tulumovic.kuhin ja.najRecept() +77
tulumovic.kuhin ja.Page_Init(Ob ject sender, EventArgs e) +56
System.Web.UI.C ontrol.OnInit(E ventArgs e) +67
System.Web.UI.C ontrol.InitRecu rsive(Control namingContainer ) +241
System.Web.UI.P age.ProcessRequ estMain() +174
Version Information: Microsoft .NET Framework Version:1.1.432 2.573;
ASP.NET Version:1.1.432 2.573
----------------------------------------------------------

Please note line saying:
[InvalidOperatio nException: 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 ?