Recently, two of my Office 2003 Apps (Outlook and Excel) started taking 3-7 seconds whenever I copied something within the document... even a single character. Using ctl-C, drag-and-drop or pull-down menu makes no difference. If something is copied, the long lag is there. I tried running with very limited services and that FIXES THE PROBLEM, but I can not figure out which one causes it. And once I do find it, how do I know if it is ok not to run it anymore? STRANGER YET, every so often, there is NO perceptiable lag, and I can't find anything that would allow these brief glimpses of proper operation.

You may want to defragment, and also check for malware along with posting a HijackThis log.