What are the minimum requirements for StackRegent?

Windows Server 2016 (build 14393) or later, Standard or Datacenter, with Desktop Experience or Server Core, an x64 CPU, a fixed public IP address and outbound HTTPS for the license check. For anything beyond a test server, plan on at least 4 cores and 8 GB of RAM on SSD storage.

Does StackRegent run on Windows 10 or Windows 11?

It is made for Windows Server. On a client edition the installer prints a warning, and features that need server roles, such as the Microsoft DNS Server, are not available. Use Windows Server for anything you host for others.

Does StackRegent support Windows Server Core?

Yes, on all four releases. The installer skips IIS Manager and the Service Monitor tray app; you manage the server from the panel and with the stackregent command line.

Can StackRegent run on a VPS or in the cloud?

Yes. It runs on any virtual or physical Windows Server that meets the requirements. Open the ports in the provider's security group or firewall as well as in Windows.

Which ports must be open for the StackRegent panel?

TCP 9443 for the panel, and TCP 80 and 443 for websites and Let's Encrypt. Open mail, DNS, FTP and Web Deploy ports when you install those components; the table above lists each one.

Can I use an existing SQL Server instead of SQL Server Express?

Yes. Add it under Tools & Settings › Database Servers with Add remote server, using a login that may create databases and logins. It can then be the default SQL Server for new databases.

System Requirements for Windows Server

Supported Windows Server versions#

Release	Build	Notes
Windows Server 2025	26100	Every feature, including TLS 1.3 and HTTP/3 for websites. See install on 2025.
Windows Server 2022	20348	Every feature; the release StackRegent is tested on end to end. See install on 2022.
Windows Server 2019	17763	Websites serve TLS 1.2 at most; no HTTP/3. Built-in OpenSSH client for Git over SSH. See install on 2019.
Windows Server 2016	14393	Websites serve TLS 1.2 at most; no HTTP/3; Git uses its own SSH client. See install on 2016.

The installer refuses builds older than 14393. On a client edition of Windows it prints a warning, because StackRegent is made for Windows Server and some features rely on server roles such as Microsoft DNS.

Editions and installation options#

Standard and Datacenter both work. The panel does not use any Datacenter-only feature, so the choice depends on your Windows and virtualization licensing, not on StackRegent.
Desktop Experience and Server Core both work. On Server Core the installer skips IIS Manager and the Service Monitor tray app; everything else, including the panel, runs the same. You manage the server from the panel in a browser on another computer, and from the stackregent command line.
Install on a fresh server that StackRegent will manage, without another hosting control panel on it.
Do not use a domain controller. Every subscription gets a local Windows user of its own, and a domain controller has no local accounts.

Hardware#

Microsoft's minimums for Windows Server are far below what a hosting server needs. What matters is how many sites and mailboxes you host and what they run, so treat these as starting points rather than measured limits:

Resource	Test or lab server	Production hosting server
CPU	2 cores, x64	4 or more cores
Memory	4 GB	8 GB or more
System disk	SSD with room for the components	SSD, sized for websites, mail and databases
Backups	Same disk	A separate disk or remote storage

Why these numbers:

Memory. Every subscription runs in its own IIS application pool, and each pool's worker process reserves memory before it uses it. The installer sizes the panel's own database buffer by RAM (larger at 4 GB and again at 8 GB) and raises a fixed page file that is smaller than the RAM, so sites do not fail with "The paging file is too small" while memory is still free.
Databases. Microsoft SQL Server Express, which StackRegent can install, has Microsoft's own limits: 10 GB per database, about 1.4 GB of memory for its buffer pool, and the lesser of one socket or four cores. For bigger databases, add a full SQL Server as a remote database server under Tools & Settings › Database Servers.
Disk. Backups stored on the server go to C:\Program Files\StackRegent\var\backups by default. To put them on another disk, set backup_dir in etc\stackregent.json as described in the backups chapter.

Per-subscription CPU, memory, disk I/O and process limits share the hardware fairly once it is in use; see the resource limits chapter.

Network#

A fixed public IPv4 address. Add more addresses to the network adapter in Windows for dedicated IPs; IPv6 addresses work too and get AAAA records in new zones.
Outbound HTTPS to panel.stackregent.com for the license check and updates, to the component vendors (for example windows.php.net and the MariaDB download site) and to Let's Encrypt. Without it, the installer cannot download MariaDB and the panel cannot check its license.
Outbound port 25 for mail to other servers, or a smarthost that accepts mail on port 587 if your provider blocks port 25.
Time synchronization over NTP (UDP 123). The license check, certificates and two-factor codes need a correct clock.
Reverse DNS (PTR) for the mail IP address, set by your provider to the mail host name.

Network ports StackRegent uses#

The installer and the panel create the Windows Firewall rules for the services you install. If a cloud security group or a hardware firewall sits in front of the server, open the same ports there.

Port	Protocol	Service	Opened by
9443	TCP	StackRegent panel (HTTPS)	Installer
9080	TCP	Panel HTTP, redirects to HTTPS	Installer
80, 443	TCP	Websites; port 80 also serves Let's Encrypt validation	Installer
443	UDP	HTTP/3 for websites, on 2022 and 2025 only when you switch it on	You
9444	TCP	Website Preview	Installer
9445	TCP	phpMyAdmin with single sign-on	phpMyAdmin component
8172	TCP	Web Deploy publishing	Web Deploy component
21 and 49152–65535	TCP	FTP and FTPS, with the passive range set under FTP Settings	FTP component
25, 465, 587	TCP	SMTP and mail submission	MailEnable component
110, 995	TCP	POP3 and POP3 over TLS	MailEnable component
143, 993	TCP	IMAP and IMAP over TLS	MailEnable component
53	TCP and UDP	DNS server	DNS component
3306	TCP	MariaDB, only if you open remote access	Database Servers page
1433	TCP	SQL Server Express, only if you open remote access	Database Servers page
3389	TCP and UDP	Remote Desktop, or the port you moved it to	Windows

Two ports stay on the server and must not be opened: 8306 (the panel's own MariaDB, bound to 127.0.0.1) and 783 (SpamAssassin, bound to 127.0.0.1). Once installed, Tools & Settings › Firewall lets you limit each service to listed addresses; see the security checklist.

DNS#

A host name for the server, such as server1.example.com, with an A record pointing at its IP address. The panel uses it for its own Let's Encrypt certificate, and mail uses it in the SMTP greeting.
Name servers, if the server hosts DNS. New zones get ns1.<domain> and ns2.<domain> from the template. If you offer DNS hosting, register name server host names (for example ns1.example.com and ns2.example.com) with glue records at your registrar, and change the template's NS rows to match. A second, independent name server is strongly advised; zones can be transferred to it.
Customers' domains either use your name servers or keep their DNS elsewhere and point A records at the server. Let's Encrypt certificates are issued only for names that already resolve to the server.

Software StackRegent brings with it#

You do not need to install anything before the installer. It adds the IIS role, the Visual C++ 2015–2022 runtime when missing, MariaDB for the panel's own database and the hosting components you choose. Windows PowerShell 5.1, which every supported release includes, runs the installer. Everything else comes from Tools & Settings › Server Components after installation, with downloads checked against checksums or Microsoft signatures.

StackRegent system requirements