|Let's straighten out the terminology first.|
It is not your hard drive that is beeping. Your motherboard produces POST beeps on startup that indicate whether or not the system passes/fails Power-On-Self-Test. (POST)
4 beeps indicates a problem and the exact meaning depends on the version of BIOS installed on the motherboard. BIOS = Basic Input Output System. It is the dragon-brain of all computers and they do not boot up into an operating system unless POST is successful.
Is your system a brand-name unit such as Dell or Gateway etc? If so then post back with details of the make/model number and we might be able to help you identify the bios version and beep error code. Q? Are the four beeps all short or a mix of short/long?
How long ago did you wipe down the keyboard with wet tissue and have you attempted to dry it out using for example a hand-held blow dryer? Was rhe PC running when you wet the keyboard? Do you have another keyboard you can try? ( most systems are set so they will not boot without a working keyboard)
Goin' Fishin' (Some day)