Is my computer case mATX or ATX?

My computer is a Compaq Sr1151NX.


The motherboard is mATX form factor but im not sure about the case.Is my computer case mATX or ATX?
most mATX motherboards can fit into the ATX cases.


but ATX motherboards cannot fit into the mATX cases.Is my computer case mATX or ATX?
ASUS PTGD1-LA Socket 775 ATX MB w/P4 3.4GHz








General Features:


Supports Hyper-Threading Technology


Supports up to 3.4 GHz CPU


Intel Pentium 4 CPU 3.4 GHz pre-installed


Socket 775


ATX Form Factor


800 MHz Front Side Bus


Supports up to 4GB DDR266/333/400


One FDD connector


RealTek ALC650 8-channel audio with Intel High Definition Audio CODEC


Supports 4 Serial ATA devices


Realtek RTL8101L LAN


10/100 Mbps Fast Ethernet controller








Expansion Slots:


One (1) PCI Express x16 graphics PEG slot


Three (3) PCI slots


No AGP slot








I/O Ports:


One (1) parallel port


One (1) video (VGA) port


Two (2) PS/2 ports


One (1) RJ-45 Fast Ethernet LAN port


One (1) IEEE 1394 port


Four (4) USB Ports


Six (6) audio ports support 8-channel audio configuration








Installed Processor:


Intel P4 LGA-775 CPU


3.40 GHz/1M/800








Supported Processors:


Intel LGA-775 CPU


800 MHz FSB


3.4 GHz max








Regulatory Approvals:


FCC


CE


BSMI








Package Includes:


ASUS (HP OEM) Socket 775 Motherboard


Intel Pentium 4 3.4 GHz CPU








Notes:


Model: PTGD1-LA (Grouper)


HP P/N: 5187-7616





this is what is in your case. It's a micro atx board.





If there is alot of room below the last white pci slots then your case has room for a regular atx mobo. If it's really tight at the bottom this is the largest board you can put in this case.
it doesnt matter if the case is atx or matx...


as long your mobo fit in it...


but, usually, if your mobo is mATX, the case also mATX