Upon setting up a new Virtual Desktop with Windows, it's highly recommended to change your initial password promptly. The initial credentials created during the setup are stored in the hosting provider's database, and these are not intended for long-term use. To ensure your privacy, you should be the sole person who knows your password.
Make sure to set a strong password (at least 8 chars long, with symbols, digits, upper and lower cases) otherwise your Virtual Desktop could be hacked in a few hours/days.
Please note that there is no way to change the password from outside and we can't do it on your behalf. If you have lost your password please have a look at this article.
Here's a guide to changing your password:
Change or manage passwords in Windows 10
To change your password, go to Start > Settings > Accounts > Sign-in options.
Select Password, and then select Change.
Change or manage passwords in Windows 7
To change your password, go to Start > Control Panel > User Accounts. Click on Change your password. (If you wish to change the password for another user, click on Manage another account instead.)
Enter your current Windows password, then enter the new password and confirm it. Click Change Password.