I have had this issue since late September, and it hasn't gone away. I am building a PC, and I can only rely on what I visualize would be compatible. I have tried many things, using a different internet browser, using a different device, etc. It just says PCPartPicker temporarily unavailable. I decided to go deeper and try using 3G on a mobile device. It did work, but still, I need it on my computer. Then I tried using a free online proxy server. It DID work, but it was as slow as heck and not everything was displaying. Its something related to this router I am on. I know the website is online and I have pinged it. If anyone could help, it would be great! Thank you very much!