Problem with moffice.exe?

I have a problem with my file moffice.exe. It's kind of an on-and-off problem. Sometimes, when I start my pc, a message appeared saying that moffice.exe has encountered problem. But after restoring my pc and restarts it, the message didn't come out during restarts. However, sometimes later, the message would come out again. Kindly help me in understanding and solving this problem?

My pc spec - Pentium 4 1.5Mhz, RAM 256Mb, Hard Disk 80Gb.

Thank you.