Help me please most my files not open as .dcom on them

[repacpete]

im running windows 7 ultimate 32bit sp1
i dont know how to remove it in mass amounts is there a program or a way
ive done my basic ones but need sort the rest so i can save all lost with .dcom at end
is there a way im 50 used to be gd with pc my memory of doing this is gone brain doesnt work properly so i have to do step by step on everything.
Please help if you can

[accodinguk]

You will need to be more clear with the issue raised. So far im finding it hard to understand.