To uninstall SSEE:
Start Registry Editor, and then locate the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall

In the left pane, click each GUID.
For each GUID that you click, look for a display name in the right pane that matches “Microsoft SQL 2005 Embedded Edition”.

When you see a display name that matches the name, copy the value of the Key named “UninstallString”
Open a Command-Window (Start->run->cmd)
Paste the Copied string.
Append “CALLERID=OCSETUP.EXE” e.g. “MsiExec.exe /X {BDD79957-5801-4A2D-B09E-852E7FA64D01} CALLERID=OCSETUP.EXE”

There you go
Don’t forget to reboot.
Hope that helps
Patrick

[Source: http://www.sharepointblogs.com/]

https://connect.microsoft.com/programdetails.aspx?ProgramDetailsID=1384