System restore only work in safe mode

I dont understand why I cannot use system restore in normal mode. If I try to
restore I get the message that system restore could not restore to this point
choose another point, but if I go on Safe mode then everything works fine. I
need to restore my system to an ulterior date because it takes about 10
minutes for window to load on startup and I can not acces safe mode by
pressing the F8 key.
If i try to close system restore and reopen it like sugested I will loose my
restore point wich is not good since I need to restore it to an ulterior
point what can I do ?