My search to cure the IE7 not responding problem (on Vista64) lead me to this page. Further search lead me to this page (don't click yet)
http://windowshelp.microsoft.com/Windows/en-US/Help/8038f9ac-9bf9-4809-8d75-fc42818d8af71033.mspx
The title of this page is "Windows Vista Help: Repair Internet Explorer" and it is one of the more complete guide on how to resolve browser add-on problems (w/o using regedit). Ironically, this page consistently caused IE7 to "not responding" problem on my system until I found out that the BitComet add-ons were the source of the problem. The text vresion of the guide is included here (if you cannot open the guide)
Repair Internet Explorer
Applies to all editions of Windows Vista.
Which edition of Windows Vista am I using?
If you can open Internet Explorer but cannot get to sites on the Internet, or you find that web browsing is very slow, you should first make sure that you have a good connection to the Internet. If your Internet connection is good but Internet Explorer is still having problems, try the following:
Disable all add-ons
While browser add-ons can enhance your online experience, they can occasionally interfere or conflict with other software on your computer. Try starting Internet Explorer without add-ons to see if the problem goes away. Here's how:
• Right-click the Internet Explorer icon on the desktop, and then click Start Without Add-ons.
If you do not have an Internet Explorer icon on the desktop, click Start, click All Programs, click Accessories, click System Tools, and then click Internet Explorer (No Add-ons).
If disabling all add-ons solves the problem, you might want to use Add-on Manager to disable all add-ons and then turn on add-ons only as you need them. This will allow you to figure out which add-on is causing the problem.
To open Add-on Manager
1. Open Internet Explorer by clicking the Start button , and then clicking Internet Explorer.
2. Click the Tools button.
3. Click Manage Add-ons, and then click Enable or Disable Add-ons.
Reset Internet Explorer settings
If disabling add-ons doesn't solve the problem, try resetting Internet Explorer back to its default settings. This removes all changes that have been made to Internet Explorer since it was installed, but it does not delete your favorites or feeds.
1. Close all Internet Explorer or Windows Explorer windows.
2. Open Internet Explorer by clicking the Start button , and then clicking Internet Explorer.
3. Click the Tools button, and then click Internet Options.
4. Click the Advanced tab, and then click Reset.
5. Click Reset.
6. When you are done, click Close, and then click OK.
7. Close Internet Explorer and reopen it for the changes to take effect.
Run the Microsoft Malicious Software Removal Tool
Malicious software and viruses can often cause Internet Explorer to slow down or stop working.
• If you are able to access the Internet, use the Malicious Software Removal Tool to check your computer for viruses and malicious software.
Update Internet Explorer
Running Windows Update can often correct problems by replacing out-of-date files and fixing vulnerabilities.
1. Open Internet Explorer by clicking the Start button , and then clicking Internet Explorer.
2. Click the Tools button, and then click Windows Update.
3. Follow instructions on the Windows Update page.
Note If you cannot open Internet Explorer or if it opens briefly and then closes, the problem might be caused by low memory, or corrupted or missing system files. Restart your computer to clear the memory and then open Internet Explorer by itself.