If you are experiencing difficulties with loading videos, one of two things may be happening:

1. If you receive an error that says your account is not active or valid, we may need to add your NSID into the database of users. Please send an email and include your name and NSID and describe your issue.
2. If the videos seem to not be loading or if you are prompted over and over again for your NSID, you may need to follow the steps listed below. Once you have enabled 3rd Party Cookies for the Virtual Lab, please restart your browser and if you still have troubles, please feel free to send us an email as described in number one.

Set your browser to accept cookies

A cookie is a small piece of information stored by your browser to help identify you. Many Yahoo products use cookies to keep you signed in as you move from page to page, among other things. If your browser is set to reject all cookies automatically, you won't be able to sign in to some Yahoo products. Instead, you may see an error message. If your browser is set to not accept cookies, you should change it to accept (or "enable") cookies.

Note: If you are running a browser other than those listed and would like more information about enabling cookies, refer to your browser's help file.

IE 10.0 for Windows and above

Operating systems:
- Microsoft Windows 7 and 8

1. Select the options gear in the top right | Internet Options.
2. Under "Browsing History," click Delete.
3. Ensure the boxes are checked for Temporary Internet Files and Cookies.
4. Click Delete at the bottom of the window.
   Note: This is located to the left of the "Cancel" button, which is highlighted by default.
5. Close and restart your browser.

IE 9.0 for Windows

Operating systems:
- Microsoft Windows Vista and 7

1. Select Tools | Internet Options.
2. Under "Browsing History," click Delete.
3. Ensure the boxes are checked for Temporary Internet Files and Cookies.
4. Click Delete at the bottom of the window.
   Note: This is located to the left of the "Cancel" button, which is highlighted by default.
5. Close and restart your browser.

IE 8.0 for Windows

Operating systems:
- Microsoft Windows XP, Vista and 7

1. Select Tools | Internet Options.
2. Under "Browsing History," click Delete.
3. Check the boxes for Temporary Internet Files, Cookies and History.
4. Click the OK button at the bottom of the "Internet Options" window.
5. Close and restart your browser.

IE 6.0 and 7.0

Operating systems:
- IE 6: Windows 2000 and XP
- IE 7: Windows XP

1. Select Tools | Internet Options.
2. Select the Privacy tab.
3. Ensure the security level is set to Medium or Medium-Low.
4. Click OK.
5. Close and restart your browser.

Firefox 2.0 and newer

Operating systems:
- PC Firefox 2.0 to 3.5: Windows 2000, XP and Vista
- Mac Firefox 2.0 3.5: Mac OS X 10.4, 10.5 and 10.6
- PC Firefox 4.0 and newer: Windows 2000, XP, Vista and 7
- Mac Firefox 4.0 and newer: Mac OS X 10.5, 10.6 and 10.7

1. Choose the menu option for your computer:
   - PC: Select Tools | Options.
   - Mac: Select Firefox | Options.
2. Select Privacy.
3. Choose the option for your version of Firefox:
   - Older versions of Firefox: From "Firefox will" menu, select Use custom settings for history.
   - Newer versions of Firefox: Skip to the next step.
4. Ensure the Accept cookies from sites box is checked.
5. Ensure no Yahoo! sites are listed under the "Exceptions" button.
6. Click OK.
7. Close and restart your browser.

Safari 3.0 and newer

Operating systems:
- PC Safari 3: Windows XP and Vista
- PC Safari 4 to 5: Windows XP, Vista and 7
- Mac Safari 3 to 4: Mac OS X 10.4, 10.5 and 10.6
- Mac Safari 5: Mac OS X 10.6 and 10.7

1. Choose the menu option for your computer:
   - PC: Select Tools ( gear icon) | Preferences.
   - Mac: Select Safari ( gear icon) | Preferences. 
2. Select the Security tab.
3. Select the cookies option Always.
4. Close the "Preferences" window.
5. Close and restart your browser.

Operating systems:
- Windows XP, Vista and 7
- Mac OS X 10.5, 10.6 and 10.7

1. Select Tools  | Settings.
   - The "Settings" page displays.
2. Under "Privacy," select Content settings.
   - The "Content Settings" window displays.
3. Under "Cookies," select Allow local data to be set.
4. Click Done.
5. Close and restart your browser.