You can try unregistering and re-registering "C:\Program Files\Common Files\System\OleDB\msdasql.dll"
using regsvr32.exe and see if that helps.
(Updated)
Do you use windows authentication to connect in SQLServer? If so, look up subinacl.exe and see if your permissions are not sufficient after the restore operation you did.
.·*´¨)
.·`TCH
(..·*
010000110101001101101000011000010111001001110000010011110111001001000010011101010111001101110100
"When the debate is lost, slander becomes the tool of the loser." - Socrates
Vita contingit, Vive cum eo. (Life Happens, Live With it.)
"Life is not measured by the number of breaths we take, but by the moments that take our breath away." -- author unknown
"De omnibus dubitandum"
