Remove any malware on your computer. This includes (sorted by how much time you need to remove the malware):

Malware popups (1 minute)
Scareware (1 minute)
Adware (30 minutes-1 hour)
Spyware ( 1 hour-2 hours)
Trollware- this is anything that doesn't allow you to move your mouse/type. One example is Mousetrap, a malicious program that freezes your mouse. Read more on mousetrap here: https://www.bullguard.com/bullguard-security-center/pc-security/computer-threats/mousetrapping.aspx (1-2 hours)
Ransomware- (varies, up to 2 days)
Note: I only perform this service virtually- I will not be able to control your mouse/keyboard. I will just give you advice.