Longer time to load windows?

Since I got my new computer back in November everything loaded extremely quickly, including windows with a rough estimate of 2 seconds of that screen where the orbs form the windows logo. Ever since last week the time to load windows has increased to a range within 15-20 seconds and I'm not entirely sure why. If anyone could shed some light on what's happening it would be greatly appreciated.

 Spoiler

posting that just in case it matters although I haven't changed anything since I got the computer

try defrag, & memory check to clean out some junk. delete cookies, temp files & cache.

Mine loads Windows slower when I have my external plugged in, if that helps.

try defrag, & memory check to clean out some junk. delete cookies, temp files & cache.

I've defragged/ccleaned/scanned and they didn't help out. However I did do a little bit more searching on Google and now I'm back to loading fairly quickly, around 4 seconds. Hopefully it sticks for a while.