I've recently bought a Dell Inspiron 660 running Windows 8 which has been working well. However, in the last week, it's been randomly switching to just a black screen and no keys / mouse etc have any effect. The only solution is to reboot, which works.

Before you try reinstalling the OS, it might be helpful to do a little troubleshooting to determine if this is a hardware or software problem. Reinstalling Windows means you'll lose all your data on the hard drive, unless it's backed up on external media first.

I purchased my Inspiron 620 about a year ago, and I wanted to upgrade from the stock power supply, and I wanted to know if this power supply would work with my configuration: http://www.newegg.com/Product/Product.aspx?Item=N82E16817148040