I have the same problem. I have SQL 2008 installed on my local system. Created a windows local account and in SQL server added this account with sysadmin access.

I have changed the account in the analysis servesis services(configuration manager) to this account.

Now I am able to start and stop services but when I go nad try to process any dimension in SSAS I get the above error.

OLE DB error: OLE DB or ODBC error: Login failed for user '029W-8MS0CK1\srini'.; 28000.

Process failed.

Any suggestions appriciated

Thanks for reading.