I will say yes you can. But you need do the home works first.
1) Open the case, measure the space for the gtx750ti, because the gtx750ti is the short one (9.5"), but just make sure. http://cdn.overclock.net/e/ee/500x1000px-LL-ee575342_P1010034.jpeg You can find the gtx750ti dimensions from the manufacturer website.
2) For the PSU, open the case too check the PSU to see its specifications. And using the HWiNFO64 to check the +12V, +3.3V and +5V, all the PSU have standard voltage tolerances range, if your PSU is within the range and you are fine, otherwise you need the new one. The gtx750ti need a 400W PSU with 20A on the +12 rail.
HWiNFO64 http://www.hwinfo.com/download.php
Power Supply Voltage Tolerances...
I will say yes you can. But you need do the home works first.
1) Open the case, measure the space for the gtx750ti, because the gtx750ti is the short one (9.5"), but just make sure. http://cdn.overclock.net/e/ee/500x1000px-LL-ee575342_P1010034.jpeg You can find the gtx750ti dimensions from the manufacturer website.
2) For the PSU, open the case too check the PSU to see its specifications. And using the HWiNFO64 to check the +12V, +3.3V and +5V, all the PSU have standard voltage tolerances range, if your PSU is within the range and you are fine, otherwise you need the new one. The gtx750ti need a 400W PSU with 20A on the +12 rail.
HWiNFO64 http://www.hwinfo.com/download.php
Power Supply Voltage Tolerances http://pcsupport.about.com/od/insidethepc/a/power-supply-voltage-tolerance.htm
Yes just take the case off by thumb screws, than install gpu on pcie x16. Apply screws to secure gpu, and close the case. Install drivers from disk and check website for updates. Psu wattage should be fine as long as u have 400w and a 12v rail with 18amps minimum.