|"Is it the agp slot itself or the original hp casing that is restricting me to get the cards installed."|
The case limits the cards to being low profile. A regular case doesn't.
The cards will work in the mboard in a regular case that can use regular height cards.....
- assuming the AGP slot is the same length as on the cards, or if the slot is longer - oddball AGP Pro cards and slots for them that were made for a few years have more contacts and have a longer contact strip - regular AGP cards work in AGP Pro slots but not visa versa.
AGP vs AGP Pro
- if the card call be plugged into the slot physically - if the slots in the contact strip fits any dividers in the slot
Types of AGP slots:
- if they are 4X or 8X capable chipsets on the cards.
- if the card is otherwise compatible
All 8X slots and 8X AGP card chipsets are also 4X capable. Older AGP video chipsets are sometimes 1X / 2X / 4X / 8X capable - e.g. ATI Radeon chipsets previous to 9500. Older mboard main chipsets can use the video chipset in any of those modes, but newer main chipsets can sometimes only use 4X / 8X capable card chipsets - the 1X / 2X support of older video chipsets can damage such a main chipset in some cases.
I would need to know which video chipsets are on the cards.
"In my google searches I found out that this motherboard can also be fillted in normal casings and also takes normal power supplies. Is it true ?"
Yes, I believe the mboard series was used in both smaller sized and regular sized cases, depending on the HP model, and proprietary wired PSs and power sockets on mboards to suit were not being made anymore at the time they came out, except for oddball server mboards.