AV update stay at 90 % and make system freeze


I have an issue on Windows Seven 64 bit with 4.0.138377.779, when AV update run, it stay at 90 % for 5 to 10 min (or more). Lot of applications freeze and if I run some other it takes lot of time to run.
I try to reinstall CIS, but I have the same issue. When update finish, all works.
On an another computer running on vista 32 bit, I didn’t see something like that for the moment.

Now it stay at 90 % forever.

I rollback this computer to 3.14.