Don't know much about upgrading PC's, so I'll try to explain as best I can. I'm looking to upgrade the present processor I have in my PC which is a Intel Celeron 1.7GHz. I was looking at maybe a Celeron 2.4 or 2.6. The motherboard I have is a IM845GL, if that means anything to anybody. The book states it will take an "Intel Pentium 4 Processor in the mPGA 478 pin package". This doesn't mean much to me. What I'd appreciate knowing is which chip should I buy. I realise the Pentium 4 is a better chip than the Celeron, but I'm lost as to which chip I should buy. I've seen loads of Celeron chips for sale on ebay, but the description always states, make sure it is the correct chip for your motherboard, as there is no refunds. I just don't want to go and buy a chip that might not work. Any advice would be greatly appreciated. Thanks.