My Mac mini has decided to continuously drop off my wifi network and is incredibly slow to open a web page. Wifi is working perfectly with other devices.

Hi my Mac mini will not stay on the network today and is slower than a pc to lad a web page.

I've followed various suggestions off the web and still have the same problem. 1 second the network is available and working slow and the next it says in network diagnostics that ISP has failed. The router is fine as I'm using an iPad and iPhone and all is working perfectly at +5 Mbps however when I try to open yahoo in safari it take about 5 minutes to open the page and then when I try to create a new mail I get the same Tim delay and then can't enter a send to address!

I've never managed to sort out email either but it not for a lack of trying about 30 different suggestions.

I'm fairly new to mac and am getting very very frustrated with not being able to solve these problems.

Can anyone please steer me towards a step by step or screen by screen resolution please please please help?