Umm, who in hades told you that?

MySQL is completely separate from plesk and isn't dependent on it or required by it or for it.

That's nuts, you should be on a linux server, you can run it on a windows server, as long as PHP and MySQL are installed.

But I would not.

A friend of mine who I thought knew what he was doing... obviously not i presume?

vBulletin needs to run on a Linux server, and shouldn't be mentioned in the same breath as plesk, EVER.

You can run it on windows but why the heck ever, ever would you?

Oh god I feel so embarassed now excuse me...

https://vborg.vbsupport.ru/external/2013/12/2.gif

NO, no... No need for that friend we're here to help you. We can get you going we just need more information.

First off, my assumption could be wrong but do you know if you are on godaddy's linux hosting or windows? Is it the economy shared plan or the deluxe plan?

We can work with plesk, it's just that alot of us old timers haven't even heard of it for years - we've reacted like you showed us a turd in a punch bowl I'm afraid. That's on us. Don't bail, we're the best folks ever for helping folks.

Aha I see, in that post I was kinda half joking half being serious. I am on Windows hosting and on the deluxe plan. What are the benefits of linux may I ask also, just out of curiosity?

Edit: Sorry I keep on sniggling at " showed us a turn in a punch bowl"

That's a debatable topic and really isn't all that relevant to vBulletin, it's just two schools of thought. vBulletin will run on windows just fine. Now, to your issue:

First please be advised if you are using Internet Explorer as your browser, it is known to display an Internal Server Error when there isn't one. Try using another browser first to eliminate this possibility.

If this isn't it, then the next step is to take a look at your apache error log. On a Plesk server this log should be found in: /etc/httpd/logs/

IMO linux it much better, I don't know of too many people running vBulletin on a windows server, but there could be a few.

Did you set up your database following these instructions from vBulletin?

http://www.vbulletin.com/docs/html/plesk_database