If you get a 500 Error or "Internal Server Error" after you have just installed Word Press and have gone to your Admin to login here is the simple fix.
Go you your admin directory commonly titled "WP-ADMIN" open it up. Now you want to create a file called "php.ini". Inside this file you want to place the single line
"memory_limit = 32M ;" (without the quotes).
You can do this on your local computer in notepad and upload it or you can do it LIVE in your cPanel or favorite FTP program if it allows you to create and edit a file.
Thats it. now go login..