Please capitalize where necessary: when a new version is is released, you have to apply changes to your customers' existing database so new code can work for them, too.
A: When a new version is is released, you have to apply changes to your customers' existing database so new code can work for them, too.

Q: its only major flaw is that it doesn't take the package pool into account, because that was implemented by james troup after it was written.

A: Its only major flaw is that it doesn't take the package pool into account, because that was implemented by James Troup after it was written.

Q: parkmuseerne is a museum district in the heart of copenhagen. located in and around three beautiful parks you will find six museums: the david collection, the cinematheque, the hirschsprung collection, smk (national gallery of denmark), natural history museum of denmark and rosenborg castle.
A: Parkmuseerne is a museum district in the heart of Copenhagen. Located in and around three beautiful parks you will find six museums: The David Collection, The Cinematheque, The Hirschsprung Collection, SMK (National Gallery of Denmark), Natural History Museum of Denmark and Rosenborg Castle.

Problem: instructions: a-d / left-right arrow or mouse (change in options)
Can you repeat this sentence, but capitalize it?
Answer: Instructions: A-D / left-right arrow OR Mouse (change in options)

Text: how far in advance do i need to register for my language course?

Correct capitalization: How far in advance do I need to register for my language course?

Text: including air conditioning, heating and free wifi. the price does not include taxes.

Correct capitalization:
Including air conditioning, heating and free Wifi. The price does not include taxes.