I have DDE links up and running OK on my laptop.

Laptop specs:
-Excel 2002 SP3
-Windows 7.

The DDE links are to the Think or Swim brokerage server through their downloaded trading platform ‘TOS’. Side note: this is a great platform.

Typical DDE formula: =tos|last!spx

The problem is with my new computer. I transferred the spreadsheet files from the laptop to the new one.

New computer specs:
OS: XP
TOS installed, open and running.
Excel 2003 SP3

Symptoms:
-When I load spreadsheet with DDE links - it locks up and then gives: (Not Responding).
-I am not getting any error messages in the cells with the formuals.

Attempted solutions.
-Restarting Excel
-Rebooting
-Deleting the TOS file; 'Usergui' and reloading TOS. (This is the typical TOS tech instruction).
-Entering one formula in an otherwise blank worksheet. The formula cell in Excel after I hit ‘Enter’ doesn’t close the cell, Excel appears to freeze before the formula can execute.
-I contacted TOS tech support yesterday but there is no response yet. They are most likely to confirm DDE is working properly and it must be something on my end that is not their responsibility.
-Security setting = Medium
-Downloaded ‘DDESPY’ but it appears that the problem never triggered DDESPY.

None of the above fixed the problem. It is still locking up whether TOS is open or not.

Any suggestions?

Thanks,