can't post charts

At first, this is a newbie question. Only, while I may be one, it's my computer at fault. Then, this is not a programmer's question. Yes, I figured programmers may know what to do.
Here it is. (I'm using the latest version of Windows Explorer 7, on Windows XP Home.) I had used a registry cleaner / Windows 'tweaker' software (no names, please) to speed up my computer; instead, I got the lack of use of a border-only separate-window popup.
You have four ways to post a chart: 'Attachments', 'Manage Attachments', the 'Insert Image' shape, and the 'Insert Link' shape. The first three don't work on my computer, and the last one, while usable, lacks immediacy to a possible reader.
The first two give me a separate window that is blank and keeps running. I tried right-clicking them and nothing useful showed: 'Save Picture' etc. on first, 'Undo' etc. on second. I deleted the separate window on one and tried to open another, same message, and got nothing (may be normal.)
The third's image fails to show, error message given.

I'm thinking it may be in the Explorer security area (tools->internet options->security->custom level), which to enable, disable or ask. I don't know, and need some help. I don't think it's a popup blocker, because I undid it here and restarted, and the other in 'internet options' is unchecked. I may have one from another program; I am unsure of this.

Thanks in advance.

It looks like you've narrowed things down to 2 chief suspects. I agree that popup blocker is probably not at fault.

The timing of the problem with the use of a registry cleaner raises a red flag. I hope the registry isn't screwed up. Or if it is, that you have a backup copy available.

Since a registry problem might be beyond the scope of this forum, let's take a closer look at suspect #2. If you're using a "custom" IE7 security level, try changing it to "medium security" instead. That should be quick and easy to test. If it works, great . . . if it doesn't, you haven't wasted much time.