messaging interface error

Has a win98 machine with OL2000 running on it. After upgrade os to W2K, am now getting following errors. When trying to create mail and click on to button..”MS OUTLOOK, the messaging interface has returned an unknown error”. When trying to look at properties (ei Tools-services- I received “MAIL, you need more memory or system resources” I receive same error if i try to go in via control panel- settings- mail.

Thanks