Hi did you get more information on this issue? I just ordered a brand new precision 7450 and plan to upgrade after I get it. 

@Yabin with our higher end systems, it's not unexpected for our users to upgrade parts on the system. Whilst upgrading parts on the system won't invalidate your warranty, there are certain aspects of upgrading that you need to consider regarding warranty.

If you upgrade parts i.e memory or hdd and you damage the system during the upgrade, you wouldn't be covered for the damaged component under warranty. 

Additionally, if your upgraded component fails and damages another component as a result of that, again you wouldn't be covered for that component under warranty.

If the system develops a fault and you have upgraded components and you require a warranty claim, you will be asked to return the system to it's factory configuration for testing. This was also help with the troubleshooting process as it allows other components for testing helping to narrow down the failure point.

If the upgraded components fail you would need to contact the vendor or manufacturer for support for this components. As far as I am aware, most 3rd party memory comes with a lifetime warranty. 

With regards to Precision upgrades, especially memory, please pay particular attention to our compatibility lists on the memory upgrade section of the website. We can't guarantee compatibility with all memory modules and their have been 3rd party vendors and manufacturers claiming compatibility and customers encountering POST errors when installed in the system. I believe this is due a difference between CL speeds for the memory modules and the motherboards.

I hope this clears up any confusion.

Alan