Please capitalize where necessary: the application runs both on pc and macintosh and allows seamless files exchange
A: The application runs both on PC and Macintosh and allows seamless files exchange

Q: buy airtime and host your own radio show.

A: Buy Airtime and host your own radio show.

Q: it is these fearful feelings which may make you experience others as unhelpful or downright aggressive.
A: It is these fearful feelings which may make you experience others as unhelpful or downright aggressive.

Problem: displays current value of each coin shown in currency. click the left arrow (with a minus sign) to decrease the value of each coin. click the right arrow (with a plus sign) to increase the value of each coin.
Can you repeat this sentence, but capitalize it?
Answer: Displays current value of each coin shown in currency. Click the left arrow (with a minus sign) to decrease the value of each coin. Click the right arrow (with a plus sign) to increase the value of each coin.

Text: change your password regularly eg. every 90 days.

Correct capitalization: Change your password regularly eg. every 90 days.

Please capitalize where necessary: the 1st parenthesis captures into $1 and the 2nd parenthesis captures into $2 etc
A:
The 1st parenthesis captures into $1 and the 2nd parenthesis captures into $2 etc