Entire Blog Shift to the Right

Your site looks fine in Firefox but becomes one column in IE. How about adding float:right to your sidebar and removing the left margin.
Haven’t tested this its just a thought so I hope it works.

Thanks, I’m going to try that. It’s funny though because it shifts to the right in Firefox for me – as well as in Safari… Mmm interesting…

edit: Now when I go into “editor”, it says “The requested theme does not exist.”. What is going on? I should maybe just install wordpress all over again?

Your blog is fine in IE7 except for the side bar being forced down by something too large in your posts area. Most often it is a utube video sized incorrectly.

You have other errors as well that can be checked here, https://validator.w3.org/check?uri=http%3A%2F%2Fjulienegrel.com%2Fwordpress%2F&charset=%28detect+automatically%29&doctype=Inline&group=0

Isn’t caused by youtube videos since this page which contains none is also badly rendered in IE7 https://julienegrel.com/wordpress/?s=elevating

Try modifying the CSS file via FTP upload. You are being told the theme doesn’t exist because you have removed the theme headers in style.css which are used by wordpress to identify the theme. There is no need to reinstall wordpress!

It worked for me in Firefox by adding position, clear and floating to the style (don’t know how this will render in IE)

#sidebar {
padding: 20px 0 10px 0;
margin-left: 850px;
float:right;
position:absolute;
width: 190px;
}

.narrowcolumn {
float: left;
clear:left;
padding: 0 0 20px 0;
margin: 0px 0 0 80px;
width: 400px;
}

Thank you, buddha trance, it worked! In Firefox at least.
And thank you all very much for your help.

This margin-left: 850px; will not let it work in IE7.

The page has lots of errors. You will never render successfully across browsers unless you start with validated code and work from there.

what are the attributes for #page in your css?