Hey There...........There are several factors involved in answering a question such as yours - which are mostly based on the specific agreement you have with your landlord (which should be in writing)

Here is a an excerpt that I have copied and pasted from the State of South Carolina Legislature web site (link to the site included below) that may give you some insight as to your rights. I would suggest that you read it in it's entirety before making any assumptions. As always, it is recommended that you seek the guidance of an expert in this area or contact the Legislative office directly.

Good Luck!

http://www.scstatehouse.gov/code/titl27.htm

Title 27, Chapter 40 - Landlord Tenant Act

SECTION 27 40 530. Access.

(a) A tenant shall not unreasonably withhold consent to the landlord to enter into the dwelling unit in order to inspect the premises, make necessary or agreed repairs, decorations, alterations, or improvements, supply necessary or agreed services, or exhibit the dwelling unit to prospective or actual purchasers, mortgagees, tenants, workmen, or contractors.

(b) A landlord or his agent may enter the dwelling unit without consent of the tenant:

(1) At any time in case of emergency prospective changes in weather conditions which pose a likelihood of danger to the property may be considered an emergency;

(2) Between the hours of 9:00 a.m. and 6:00 p.m. for the purpose of providing regularly scheduled periodic services such as changing furnace and air conditioning filters, providing termite, insect, or pest treatment, and the like, provided that the right to enter to provide regularly scheduled periodic services is conspicuously set forth in writing in the rental agreement and that prior to entering, the landlord announces his intent to enter to perform services; or

(3) Between the hours of 8:00 a.m. and 8:00 p.m. for the purpose of providing services requested by the tenant and that prior to entering, the landlord announces his intent to enter to perform services.

(c) A landlord shall not abuse the right of access or use it to harass the tenant. Except in cases under item

(b) above, the landlord shall give the tenant at least twenty four hours notice of his intent to enter and may enter only at reasonable times.

(d) A landlord has no other right of access except:

(1) pursuant to court order;

(2) as permitted by Sections 27 40 720 and 27 40 730;

(3) when accompanied by a law enforcement officer at reasonable times for the purpose of service of
process in ejectment proceedings; or

(4) unless the tenant has abandoned or surrendered the premises.

(e) A tenant shall not change locks on the dwelling unit without the permission of the landlord.