hit create a instance(virtual server), inside instance page
select windows OS

1. in Instance type: select t3.micro (free one)
2. then Key pair :

• create a key pair, choose a name for your key pair,
• then for key pair type select RSA (which is default for windows),
• then for private key file format, select .pem(usually for linux/windows OS'es)

3. Hit the create key pair button, then instance will be created

then we gotta check the status, then we can proceed further