The closed Dispute cannot be reopened.
You are not required to refund without a return (even if your policy is No Returns you can still demand a return).
"Fixing" the computer means it is no longer in the condition it was sent, and even if she could reopen the Dispute, which she can't, she would lose.
She can still Dispute through Paypal
Paypal demands that the disputed item be returned to the seller (if requested) and the Buyer pays for the return.
I am not sure about "original condition" when PP is involved, mostly because the buyer usually gives up when they are told to pay for the return.
No return, you win, no refund.
She might try to do a chargeback through the credit card she might have used with PP.
But that would be handled through PP and again, you can demand the return in original condition at the buyer's expense.
So.
No return. No refund.
Not in original condition. No refund.
You are being bullied.
Stop communicating, but keep all those eBay Messages. If she was sending your emails directly, copy and paste them into an eBay Message and send them back to her with a polite refusal to play her games.
Because the laptop was not returned before you closed the original eBay Dispute and because you have modified the laptop, I cannot consider a refund.
Then put her on your Blocked Bidder List and ignore her future eBay messages. But do read any that come through Paypal and respond to those with the same message about returns and modifications.
Don't be scared. Be firm. You are in the right.
