8 year old Laptop that probably had it's fair share of use and abuse. Sell him an upgrade IMO.
Unless you want to pull the machine apart, fault find and possibly source replacement parts that is......
Try this:
Start network settings; select default wireless; enter security key password; then select IP Settings and change "Enter Manually" to "Get Automatically" then click OK.
Best to go over to the Sony Vegas forums mate as many there are, and have had the same problems you're having.
https://forums.creativecow.net/sonyvegas