is this due to microsoft sql server??

i accidentally deleted the microsoft sql server.is this useful for any applications?
i have mysql installed for the database management.and after deleting it (most probably this may be the reason) for the 1st couple of times when i start my computer microsoft office configuration (setup file) automatically runs (i cancelled it). but now that does not happen and when i try to open a microsoft word or internet explorer (till now i have found with only these 2 ) the setup file tries to run again.has this anything to do with the deletion of MSSQL . actually i uninstalled MSSQL from add remove program but terminated the process in the middle and then deleted the folder manually from the program files.