Pity the old one is busted.
One of the options Dell offers is a "Transfer My PC" product, software and a cable to suck all the information, emails, documents, software & licences, accounts, passwords & login details from the old system to the new one, saving lots of hassle. It could be the best 50 or so quid you'll ever spend, but your old PC needs to be up and running.
If it's just a switch, it could be worth fixing and if it's fixed, you might save yourself 500 quid!