Check the Taskbar is not hidden down the bottom of the screen, or has been dragged/repositioned to either side...
Hover your mouse and see if the arrows appear to drag it back into place... Was the Taskbar there when the job was finished ?
Try safe mode and see if it is there also.... I have had 6 people in the shop in the last 2 weeks with botched repair jobs, by people who are supposed to be 'In the know' lol Why people actually go back to them is beyond me
They always come back to me in the end, to get the job done correctly lol
If you get stuck, give me a shout...
maxmix
PS Windows may not have been installed 100% or some files may be corrupt....