Hello folks, I got a desktop computer I bought from a family member to perform some tasks. It has an Intel Pentium 4 and 1 GB of RAM. I want to upgrade with, at least, more 2 GB of RAM. I opened the desktop, and there are 4 memory slots. 2 make mention to something like Prescott memory (I forgot to write it down... bummer... I need to re-check and now I can't) and the other 2 make mention to Hyper-Threading. Both 2 sets of slots have different colors. Those that mention Prescott are blue and the ones mentioning Hyper-Threading are purple, or something like that. The memories modules in the Prescott slots are 512MB each and 400MHz, which is the frequency accepted on those slots. The memories that need to be put on the other Hyper-Threading slots have 667MHz as frequency. I pretty much know nothing about hardware... Shameful, I know... But, I'm gaining interest ...But, the only think I knew about Prescott is the CPU and not memory (And, I was right. It was my mistake. ). Anyway... if I had DDR memory to the Hyper-Threading slots with 667MHz of frequency, everything should be fine, no? What sort of problems may I find? Hope you guys and girls don't mind this silly questions, but for me are important ones... And, without asking, I'll never learn about it. Thank you Edit: Some more info I forgot to share. I got CPUID to check on the type memory, and it reported DDR. It also said that the FSB was 200MHz, but the first time I open the box, I saw that the memory module said 400MHz and not 200MHz. So, I guess this CPUID is not that great tool? Anyway, I wanted also to ask if, and is all I've found so far in online computer shops, if the DDR is DDR2? That's all I can find for DDR 667MHz. It's all DDR2. Edit2: I finally found the web site for the mainboard http://www.ecs.com.tw/ECSWebSite/Pr...ailID=507&DetailName=Feature&MenuID=1&LanID=0 For what I can understand, the mainstream Dual-channel DDR400 are already filled, because that's what I found in the mainboard slots. So, now I can get DDR2 677MHz and place them on the other two slots. I just hope it won't blow up! lol Anyway, I think this is solved... unless something goes wrong. Maybe a moderator can close the thread, if you find it not needed to remain open? Thank you. Edit 3: Sometimes, things really get confused, without any need! The damn Prescott and Hyper-Threading words on the board, along side the memory slots, were actually for the CPU!!!! LOL Anyway, it seems that I can only use either DDR or DDR2, as this two aren't compatible.