Good advice given.
Yes, 22 million errors is saying the RAM has a problem.
First take out the RAM and clean the connectors with alcohol and a lint free cloth.
Re-seat and test again, if you get any errors you can stop the test.
Follow Gregs advice and test the RAM cards one by one to find the culprit.
Jon's tutorial is a good explanation on how to do this. RAM - Test with Memtest86+
If your still getting errors, one error is too many, then you will need to replace the RAM.
Sometimes errors can be resolved by adjusting the RAM settings, since OEM computers have a locked down BIOS you won't be able to do this.
Crucial is good RAM to get for a Dell, they guarantee their RAM to work in Dell computers.
The Crucial site has a RAM finder, just enter your Dell info and the RAM you need will come up. Crucial Memory Advisor™ Tool