The traditional approach to system monitoring would be to use SNMP. There are many tools for about every platform under the sun to accomplish this. The second approach to poll a Windows machine for system information would be to use the WMI (also available via a module by me, DBD::WMI).

As you don't seem to do the system monitoring in a "professional" environment (which to me means SNMP), there are various possibilities:

• Use SSH / SCP. With that, you can simply copy any file to the remote machine, as long as you set up passwordless keys. See Putty and pscp

• Use mail. With MIME::Lite, your Windows machine can fire off a mail to either a local mailserver which does the routing, or directly to the ISP machine. As soon as MIME::Lite has handed off the mail, you get all the benefits of SMTP, including retries and MX fallbacks if one of your servers becomes unavailable.
• Use ftp. With Net::FTP, your Windows machine can send a file to an outside machine.
• Make a HTTP POST request using (for example) LWP::UserAgent and HTTP::Request.

I would avoid writing directly into a MySQL database, as that means making MySQL accessible via the internet, which likely opens up lots of vulnerabilities for little gain.