MSWord won’t open, winword /a works

I have a Dell Dimension L-550r desktop, with pentium processor. 9.5 GB hard drive with 5.8 GB free, 128 mg ram. When I open MS Word, the machine stalls, eventually gives a “low resource” message, and then crashes. I’ve tried clearing the temp file, changing virtual memory, etc. The problem continues. If I use “Start/Run/winword /a”, the Office assistant opens, verifies my name, and starts MS Word without problem. Why does Winword /a work, but not Winword? Any suggestions to get winword to start? Thanks!!