How do I transfer Office 2010 to a new computer?

Depends;

Only if you had purchased a full retail version of Office 2010 or Word 2010, that you have the Key for, and not if it was an OEM version supplied with the old PC

See if your Key is validated here, if it is download/save the installation file before running it to install

http://products.office.com/en-GB/download-back-up-restore-microsoft-office-products

PS First uninstall any pre-installed Office trial

Palouk's point about having a Retail license is very important.  That is the only type of consumer license that allows you to transfer the installation to a new computer.

So the question is exactly how did you buy it?

To install on  a new computer you need the unique 25 character product key, a Retail license, and the generic installation file.

If you don't have the product key, we can provide links to tools that can extract it from the old computer (assuming you have it).

Here are some more links to download the installation file from:

This site has direct download links to Digital River for most of the Office 2010 installation files, Office bundles and standalone programs. You may have to scroll down to find your language.  Office 2010 Professional Plus / Office 2010 Language Pack / Project 2010 Professional / Visio 2010 Professional **http://www.heidoc.net/joomla/technology-science/microsoft/18-office-2010-direct-download-links**

NOTE: if you do not have the installation file on an “official” MS installation disk, download and save it to your HD. Then you should burn it to one or more DVDs for future use. And at the same time, write down the product key on the DVD. You need both items for future installations, say after your computer crashes and you have re-installed windows. At that point you won’t be able to extract it from the registry and won’t remember where the online account is.

Note: If you buy an Online Download you have 30 days support from MS to get the download working

Note: if you buy an Online Download from MS or an authorized reseller, Digital River or a proxy linking to DR, the Product Key and download link are saved in an “Online Account” using on your e-mail address as the log in ID.  The Product key is only kept in the account for 5 years! <snip http://answers.microsoft.com/en-us/office/forum/office\_2010-office\_install/software-savings-world-claim-to-be-a-microsoft/1dc1c8e3-e7ad-4717-8d2b-60f68554db34 >

Office 2010 / 2007 Download locations -**http://answers.microsoft.com/en-us/office/forum/office\_2010-office\_install/here-are-the-download-locations-for-office-2010/ac67aa2f-dc1c-46f4-8b1d-ca00b3f02a18** ****

https://office.microsoft.com/en-us/buy/using-the-product-key-card-FX101853163.aspx?CTT=5&origin=HA101847520

• Download 2010 using Product Key card PKC****

http://office.microsoft.com/en-us/products/microsoft-office-2010-backup-FX101853122.aspx

• Download Backup Buy Backup disk 2010 using Product Key – FPP

http://www.office.com/backup 

• Download Office 2010 Installation Backup. You will need your original Product Key, such as one from a Product Key Card.

https://office.microsoft.com/en-us/buy/netbook-FX101850729.aspx - Download Office for Netbooks (H&S, H&B, PRO, Standalone Apps)****

Direct downloads from Digital River of Trials (you need to have the Product Key already)

http://msft.digitalrivercontent.net/office2010/X17-75058.exe   Office 2**010 Home and Student x86** (English)

http://msft.digitalrivercontent.net/office2010/X17-22376.exe Microsoft Office Home and Student 2010 English 32-bit (x86):