Hello i bought a PC last year and its motherboard has crashed. Pls let me know how and where to get it replaced. my motherboard is Intel D945GCPE. Also, pls let me know about your warranty period.

Intel boards have a general warranty period of 3 years. So you can just get a replacement from the intel manufacturer through online RMA registration.as follows
Business and Home Consumers (non-Channel Members)
Please contact the retailer you purchased your product from to process your warranty claim. In the event that you are unable to process your claim through your retailer, you may contact Intel.

Prior to contacting Intel for warranty support please make sure you have completed the following steps and gathered the necessary product information. Following these steps will allow us to handle your warranty request as quickly as possible.

Make sure that your product is still under warranty and that Intel is the correct source for warranty support.

Intel sells processors, motherboards, and other products via Retail and Wholesale channels. Retail products are sold in clearly marked individual boxes and carry a warranty directly from Intel. Wholesale products are not sold in retail boxes and are typically pre-installed by a system manufacturer (ex. HP*, Dell*, Gateway*) or reseller. Intel does not provide direct warranty support for wholesale products.
If your product was sold through a wholesale channel you must contact your system manufacturer or reseller for warranty support.

Perform the proper troubleshooting steps to correctly identify the failing component.

If you do not feel comfortable doing the troubleshooting, please contact Intel and we can recommend an authorized service provider in your area.
Processor Troubleshooting guide
Desktop Motherboards Troubleshooting Guide

If you are not sure who to contact, obtain the product identification (see below) and contact Intel. We will be able to determine the proper source for warranty support.

Before you call Intel: If your retail boxed product qualifies for warranty support directly from Intel, have the following information available to give to the support agent when you call.

Proof of purchase ---the bill
Email address of customer
Name of product ---D945GCPE
Product Code ---in motherboard box
Serial number-Spec ---in motherboard box
+FPO for processors
Description of problem
Shipping address

As for as the model intel stopped it you can get DG31 seies if you want to buy a new motherboard.

You would be better off going on ebay to purchase a new mother board and you can check the warranty the provider will give for that board. Just Bing intel D945GCPE