On the advice of a salesman I bought some new ram(might of been a silly mistake). After reading up on ram I have realized that it is possible to have compatibility issues. So I'm wondering if the ram that came stock in my computer(it was a HP 2A92 (Pavilion P6000 Series) and the ram I bought(Ballistix 4 gb ddr3 pc3 - 10600 240 pin) are compatible. I would like the ram that came stock but I do not know how to find this. So hopefully my computer model would provide enough information to those who know where to look. Also I was wondering if I had to make changes to my motherboard in order to get full speeds.
Crucial is usually very good at making their memory compatible with prebuilt boxes like this. You have a good chance of it working, but not 100%. Honestly, there isn't a 100% chance of anything working, even memory directly from HP, from my experience with them. You just have to try it out and see. If it works, which is likely, great, and if not, you get to see about the vendor's return policy.
HP's are always limited in that respect. You won't be able to change any speed or latency settings in the bios. HP just sticks to the safest possible settings, and doesn't allow the users to change them. It reduces support costs for them, but also performance for you.