Office XP problems

Had office XP installed on a W2K server with terminal services enabled recently for remote users to be able to access it. All office applications except Excel works fine. Whenever an attempt was made to open Excel , the program would open without the grid lines . When I try to open an excel spreadsheet all I get is a blank screen. Have tried uninstalling Office XP, applied all the latest Office XP patches but no luck.This has happened after applying SP4 to the W2k server. Is there a way to fix this issue without having to uninstall w2k SP4?.
NOTE: Excel works fine if admin rights are given to users. Does SP4 interfere with user rights but then why only EXCEL.
Tried looking on the net for info regarding W2K SP4 related issues with Office XP but came against a blank wall. Can anyone out there help me , please ?