2-3 seconds freeze when iTunes opens

Hello,

When I launch iTunes, it opens quickly, but then it freezes for a few seconds and the "busy" icon appears on my mouse cursor. Since I open and close iTunes quite a lot, this is becoming really annoying as it happens every time. I couldn't find anyone with the same problem on Google.

I'm using iTunes 12.2.1 on Windows 8.1 64bits. The problem also happens on previous versions of iTunes.

I have an i5-4690K 3.5GHz and 16 Gb of RAM.

Windows is on an SSD and iTunes on a hard drive, but I've relocated the iTunes media folder to the hard drive.

I've tried reinstalling iTunes, the freeze comes back every time. It even came back after I formatted my PC and reinstalled Windows.

The problem still happens with a completely empty library.

The problem still happens when I'm not connected to the Internet.

The problem still happens when opening iTunes in safe mode.

Genius is turned off.

The problem does not appear on my laptop which is also running iTunes 12.2.1 on Windows 8.1 64bits.

Any help would be much appreciated!