PC is turned off now and hard drives will be wiped.
Don't do this. All malware should be there as evidence
You need to ask your wife the site from which she downloaded the malicious software. Then you need to find out the domain
All you have to do is sue either the hosting or the owner of the domain, because of which you lost your bitcoins
If your wife downloaded this voice changing software from the official website, then the likelihood of you winning the case increases