problem with Xl

Sir

I am an engineer in small company, i have one problem with microsoft excel the problem is ” i have installed office 2000 when ever i want type and dot(.)it will be converted in slash (\)so i am unble to solve the problem even i changed the keyboard but the problem remains the same i am unble to work on the excel even i cannot work on fractions or decimal numbers”

so pls get me an solution waiting for ur reply

vivek