Check these thread it will solve your issue,
Try the following
Please Uninstall SBO Client and uninstall Microsoft SQL Native Client 2008 from client PC and delete sap folder from program files and restart client PC install Microsoft SQL Native Client 2008 and then SAP Cleint setup.
After the above setup, restart all the SAP services from server and then once again restart cleint PC.
You should have Pre requisites while installing SAP B1 8.8 on Clinet PC.
If you have installed MSSQL 2008 then you must install Microsoft SQL 2008 Native Client and Dot net Framework 3.5 on Cleint PC.
Please check whether you have installed it properly or not.
Once you install just restart all the SAP services and restart your Cleint PC also.
Then try to Connect.
Also check all the Cleint PCs should be in same work group.......
I think this is sufficient to achieve.....