Q: I had to switch my Ipod to an older model and now it won't load all my ITunes songs. Any advice?

Any error messages during the sync process?

I assume the Sync Entire Music library option is selected from under the iPod's Music configuration tab in iTunes?

B-rock

Are you running on a Mac or PC?  If so, what OS are you running? Is iTunes up to date? Is the iPod plugged into a high powered USB port located directly on the PC or Mac?

B-rock

Try these steps listed below.

1. Run “c:\WINDOWS\system32\devmgmt.msc” (i.e. *Device Manager*), and leave it open for now for later use

2. Start up iTunes

3. Next, connect your iPod.

4. Go to your iPod Settings and select the “Enable disk use” option from under theSummary tab.

5. A dialog box will pop up reminding you that you’ll need to manually eject. Go ahead and hit OK

6. Hit Apply to save changes to the iPod

7. Quickly switch to the Device Manager window and right-click on any item within the window and select “Scan for hardware changes”

8. Finally, switch back to iTunes, and try re-syncing your iPod to see if it helped.

B-rock

It's the Summary tab, not the Settings menu on the Nano.  See this article for more details.

Using your iPod as a storage drive

B-rock

If the iPod still appears in Windows, trying doing a low level reformat of the iPod's drive using the instructions in this article.

http://www.methodshop.com/gadgets/ipodsupport/erase/

B-rock