A computer, even after rebooting, may not have the search bar, notifications, start menu, etc working. When this happens, normally a DCOM setting must be changed. Here's how to fix it
Since you can't search, go to C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Administrative Tools to open up Component Services
Open up Component Services -> Computers and right click on My Computer and choose Properties
Default Properties tab
Enable Distributed COM on this computer ON
Enable COM Internet Services on this computer OFF
Default Authentication level: CONNECT
Default Impersonation level: IDENTIFY
Typically you'll find default authentication got switched to NONE. QuickBooks install may be the cause of this problem in CIF.