Dell OptiPlex 745 pc tower. The tower is in good working order, but there are some issues that are best suited to someone who knows how to problem solve pc's, as I do not. I am unable to sign into the internet any longer, and I have no idea why, says there is no internet connection, but I have checked and internet is fine. On start up there is a black screen that says press F1 or F2 to continue, I have no idea why this has started to come up. Also I cannot remember hard drive size, I am not sure if its 250GB or 500GB, when I click on C drive it says information unavailable. The computer was working completely fine, then this happened, it is obviously something easily fixed, but I will leave it to someone who knows how to do this.

Computer specs :

Dell OptiPlex 745

Processor : Intel (R) Pentium (R) D CPU 3.40GHz

Ram : 4GB

64 Bit Operating System

Windows 10 Pro

DVD Rewriter