Install Free avast on different drive.

How can I install Avast free on a different drive than C. I had it installed and had to reformat my c drive. It used to need around 550 Mb now it says that 1.38 GB is not enough. My drive is partitioned with one drive only for software downloads. Or can I merge C and the other drive together?

Please disregard this post. I found the drive option under the custom option.

Having that small an amount of room on your default drive impedes your overall system performance.