Yesterday there was a power shortage in my area and my computer was in sleep mode. Usually, everything's fine but this time my computer takes a REALLY long time to log in and off. Furthermore, when I go in the devices panel it says that I need to troubleshoot my computer wich lead to nowhere because Windows can't find the proper ones (everything was working really well before the shortage).
I'll try to find the missing drivers by using an identifier but can a shortage really cause my computer to run slower?
also anything running at the time may have a damaged file. as you say it boots slow and shutdown slow. i would start by using msconfig go into the start up tab and turn everything off and then reboot. if it speeds up at start up and shut down then one of the programs in start up is damaged.