You need a half height card for the desktop form factor and that rules out all of the current SB cards except the Audigy FX. That card has support all the way back to Windows 7 and the system requirements are pretty easy to meet. Keep in mind that you have an 11 year old system and maybe an older SB card off eBay for example may also be a good choice.

its the 390 mt  i have not the ff, will it work the same with the mt?    thanks for the reply

Sorry for the confusion, when you posted desktop (which is a form factor) I assumed it was the low profile system. That opens up a wider range of SB cards. Considering the age of the system and assuming you are running Windows 10, then the Sound Blaster Z SE should work. There are drivers for OS all the way back to Windows 7 as well. The higher spec cards may work but on an old system there is no point going overboard with cards that are in the $200 and up range.

thanks again for the info, have seen those cards on ebay/amazon for reasonable price, will def  purchase.

again very helpful info.