PDF won't open when printing transactions on a Windows 8 system using Internet Explorer 10.

A. Reset the Display PDF In Browser preference.
1. Open a PDF file.
2. Right-click the document window.
3. Click Page Display Preferences.
4. From the list at left, select Internet.
5. Deselect Display PDF In Browser, and then click OK.
6. Choose Edit > Preferences > Internet, select Display PDF In Browser, and then click OK.
7. Login to NetSuite.
8. Open an transaction (estimate, sales order or invoice).
9. Print.

B. Make sure that the Adobe PDF browser add-on, AdobePDF.dll, is enabled.
1. Select Tools > Internet Options.
2. Click the Programs tab.
3. Click the Manage Add-ons button.
4. Set the Show menu to Add-ons that have been used by Internet Explorer.
5. Find and select Adobe PDF Reader. If you don't find this item in the list, reinstall Reader or Acrobat.
6. Make sure that Enable is selected.
7. Click OK.

C. If none of the previous 2 options will work, perform steps below:
Note: This should be done by an IT specialist who is preferably Microsoft certified and is familiar with Registry Editor.
1. Press Windows + R keys on your keyboard.
2. Type regedit.exe into the dialog box.
3. Click OK button.
4. A User Account Control will ask you Do you want to allows the following program to make change to this computer? Click Yes to confirm that.
5. Go to HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main.
6. Right click on TabProcGrowth.
7. Change the value to 1 instead of  0.
8. Close Internet Explorer 10 and reopen it.
9. Login to NetSuite.
10. Open an estimate.
11. Print.

Sources:
http://helpx.adobe.com/acrobat/kb/cant-view-pdf-web.html
http://answers.microsoft.com/en-us/ie/forum/ie10-windows_7/pdf-wont-open-while-running-ie10-on-windows-7/865a7ed2-ec94-4b77-a6e1-a9de6fb8f40a?msgId=b93e4aa4-702a-4b94-9d60-b23a3010eeb.