XP/MS Office problem

Hi I run Windows XP with sp2 Home edition with MS Office Small Buiness edition 2002. When I try to open a Publisher document in Word as an *rtf doc I get the following message MS Publisher has encountered a problem and needs to close. I used to be able to do this movement. I also now have a problem with downloading some programs from the internet - I have dowloaded the Vista Upgrade check and I cannot run it getting a similar message as previously. can anyone help please