Is the Ryzen 7 5825U fast enough for office work?

Yes. Its 8 cores and 16 threads handle spreadsheets, email, video calls and browser work without strain. Heavy gaming or professional rendering is beyond its integrated graphics.

Can I upgrade the RAM and storage?

HP's business design gives access to the memory slots and the M.2 drive, so both can be replaced or expanded. Check the service manual for the exact supported memory type before buying parts.

How does it compare with the ThinkPad E14?

Both are 14-inch business laptops with AMD options. The ProBook offers the same class of processor and security features; the ThinkPad line is known for its keyboard and trackpoint, while the ProBook is the simpler, more serviceable option.

Is 8GB of RAM enough?

For basic office use, yes. If you keep many browser tabs or run virtual machines, plan on upgrading to 16GB, since the memory is not soldered.

Does it have a backlit keyboard?

Backlighting depends on the exact configuration. Confirm it on the specific model listing, because HP sells the ProBook 445 G9 with and without a backlit keyboard.