i have just deleted smart client service from service structure and re-installed the smart client 2.2 rollup C . and load the extension from configuration wizard and now smart client service is not visible.
I am not sure what is meant by "deleted smart client from the service structure". For ALL versions of upgrade of Smart Client, the Release Notes for any version state to "Un-install" any previous version before upgrading/installing a new version. This is done from the MS Control Panel > Programs and Features interface on both the Smart Client Server node and all Smart Client Data Provider nodes. This will ensure that all components of the Smart Client product are removed which includes any entries in the MS Registry along with all programs. For any SC Clients, the user should also clear all the Cache entries that are brought in with a client installation even though there no actual programs installed in external client PC's. This will ensure that all residual components are removed before installing a newer version. As a note, the latest version of Smart Client is 2.2 RevD RU2, and should always be considered as the correct version when upgrading so as to take advantage of any corrections or feature additions that have been introduced.
It should also be noted that after the proper removal of the Smart Client programs from the relevant nodes, that each of these nodes should be re-started to verify the programs have been fully removed.
Deleting service objects is not really a supported operation. Groups and provider objects is another ballpark.
If you want to re-insert lost services, locate and doubleclick the corresponding .sdd file on disk (near the folder with the import files, below Program Files (x86). You may have to create service groups and providers manually.
A backup should contain the objects - use the Import Export tool's Locate... function to find them among all other in a Full Backup.
A drive image backup of your aspect server(s) might have been appropriate here. It is OK to image a disk if 800xA is "Maintenance Stopped".
But really, you should try to adhere to the official procedures...